Although obesity has been shown to be a risk factor for numerous diseases such as diabetes, coronary artery disease, and sleep apnea, most overweight and obese people do not consider themselves at higher risk for medical problems or premature death. News stories on various diets have caused confusion among many patients and health providers, leading to frustration and subsequent inaction. This course will help educate dental professionals about the epidemiology and treatment of overweight and obese patients. Using current national guidelines, the clinical management of patients will be discussed. Clinical presentation, diagnosis, behavioral, and pharmacological management will be reviewed. Surgical options for morbidly obese patients will also be examined. Steps to address and treat recidivism will be explored. Finally, current reimbursement issues will be discussed.
This course is designed for all dental professionals involved in the care of patients who are overweight or obese.
NetCE is designated as an Approved PACE Program Provider by the Academy of General Dentistry. The formal continuing education programs of this program provider are accepted by AGD for Fellowship, Mastership, and membership maintenance credit. Approval does not imply acceptance by a state or provincial board of dentistry or AGD endorsement. The current term of approval extends from 10/1/2015 to 9/30/2021. Provider ID 217994. AGD Subject Code 149. NetCE is an ADA CERP Recognized Provider. ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry. Concerns or complaints about a CE provider may be directed to the provider or to ADA CERP at www.ada.org/cerp. NetCE is approved as a provider of continuing education by the Florida Board of Dentistry, Provider #50-2405. NetCE is a Registered Provider with the Dental Board of California. Provider Number RP3841. Completion of this course does not constitute authorization for the attendee to perform any services that he or she is not legally authorized to perform based on his or her license or permit type.
NetCE designates this activity for 5 continuing education credits. This course meets the Dental Board of California's requirements for 5 unit(s) of continuing education. Dental Board of California course #05-3841-17170.
Obesity is an epidemic in the United States. As statistics indicate that the problem is growing, the purpose of this course is to educate dental professionals about the epidemiology and treatment of overweight and obese patients. Clinical management, presentation, diagnosis, and behavioral and medical management will be reviewed to assist dental professionals in encouraging their patients to lose weight and prevent obesity-related comorbidities.
Upon completion of this course, you should be able to:
- Discuss the clinical background of obesity, noting the various definitions.
- Discuss the epidemiology of overweight and obese individuals in the United States, based on age, race, and socioeconomic status.
- Describe the pathophysiology of obesity, including genetic and environmental factors.
- Identify the risk factors for and comorbidities of obesity.
- Explain the various treatment modalities for overweight/obese patients.
- Describe dietary and physical activity recommendations.
- Discuss available pharmacological agents, including indications and adverse reactions, used to treat obese/overweight patients.
- Discuss surgical options, including restriction and bypass operations.
- Explain the reimbursement climate for overweight/obesity treatments.
- Outline considerations necessary when caring for patients for whom English is a second language.
John J. Whyte, MD, MPH, is currently the Director of Professional Affairs and Stakeholder Engagement at the FDA's Center for Drug Evaluation and Research. Previously, Dr. Whyte served as the Chief Medical Expert and Vice President, Health and Medical Education at Discovery Channel, part of the media conglomerate Discovery Communications. In this role, Dr. Whyte developed, designed, and delivered educational programming that appeals to both a medical and lay audience.
Prior to this, Dr. Whyte was in the Immediate Office of the Director at the Agency for Healthcare Research Quality. He served as Medical Advisor/Director of the Council on Private Sector Initiatives to Improve the Safety, Security, and Quality of Healthcare. Prior to this assignment, Dr. Whyte was the Acting Director, Division of Medical Items and Devices in the Coverage and Analysis Group in the Centers for Medicare & Medicaid Services (CMS). CMS is the federal agency responsible for administering the Medicare and Medicaid programs. In his role at CMS, Dr.Whyte made recommendations as to whether or not the Medicare program should pay for certain procedures, equipment, or services. His division was responsible for durable medical equipment, orthotics/prosthetics, drugs/biologics/therapeutics, medical items, laboratory tests, and non-implantable devices. As Division Director as well as Medical Officer/Senior Advisor, Dr. Whyte was responsible for more national coverage decisions than any other CMS staff.
Dr. Whyte is a board-certified internist. He completed an internal medicine residency at Duke University Medical Center as well as earned a Master’s of Public Health (MPH) in Health Policy and Management at Harvard University School of Public Health. Prior to arriving in Washington, Dr. Whyte was a health services research fellow at Stanford and attending physician in the Department of Medicine. He has written extensively in the medical and lay press on health policy issues.
Contributing faculty, John J. Whyte, MD, MPH, has disclosed no relevant financial relationship with any product manufacturer or service provider mentioned.
William E. Frey, DDS, MS, FICD
The division planner has disclosed no relevant financial relationship with any product manufacturer or service provider mentioned.
The purpose of NetCE is to provide challenging curricula to assist healthcare professionals to raise their levels of expertise while fulfilling their continuing education requirements, thereby improving the quality of healthcare.
Our contributing faculty members have taken care to ensure that the information and recommendations are accurate and compatible with the standards generally accepted at the time of publication. The publisher disclaims any liability, loss or damage incurred as a consequence, directly or indirectly, of the use and application of any of the contents. Participants are cautioned about the potential risk of using limited knowledge when integrating new techniques into practice.
It is the policy of NetCE not to accept commercial support. Furthermore, commercial interests are prohibited from distributing or providing access to this activity to learners.
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#51571: Diagnosing and Treating Overweight and Obese Patients
Obesity is an epidemic in the United States. Estimates show that more than 70% of the adult U.S. population is either overweight, obese, or severely obese [1,75]. While the proportion of the population categorized as overweight has remained essentially static for the last 50 years, the numbers of obese and severely obese have increased by 52% and 128%, respectively, in just the last two decades .
Although genetic and hormonal factors play a role, the foremost causes of the obesity epidemic are unhealthy eating habits and lack of work-based and/or leisure-time physical activity. According to data published by the Centers for Disease Control and Prevention (CDC), approximately half of U.S. adults do not perform the minimum amount of exercise needed to help maintain a healthy weight and prevent diseases such as diabetes and high blood pressure; 25% of adults do not perform any exercise at all [2,3]. This is despite the fact that the benefits of exercise are well-documented, including reducing the risk of heart disease, improving glycemic control in diabetes, improving blood pressure, alleviating depression, and generally preventing morbidity and mortality. Americans are also not making ideal nutritional choices. In 2010, only about 14% of adults and 9.5% of children met nutritional guidelines for fruit and vegetable consumption .
Compounding this problem, studies have found that less than 30% of overweight patients and approximately 40% of obese patients reported ever receiving advice from their physician to increase their physical activity or reduce their weight [41,100]. Even when physicians do give advice, too often they simply admonish patients to exercise, which has been shown to have little, if any, effect. Of the 30% who did receive advice in one study, only 38% received help in formulating a specific activity plan and only 42% received follow-up support .
Although obesity has been shown to be a risk factor for numerous diseases, such as diabetes, coronary artery disease, and sleep apnea, most overweight and obese people do not consider themselves at higher risk for medical problems or premature death. News stories on various diets have caused confusion among many patients and health providers, leading to frustration and subsequent inaction. However, patients generally want to receive information on weight reduction strategies. In a study asking patients to respond to the statement, "If my doctor advised me to exercise, I would follow his/her advice," more than 90% of respondents agreed with the statement .
Numerous treatments for obesity exist. The cornerstone of any treatment regimen includes behavioral modification, focusing on diet changes and exercise regimens. Additional therapies include pharmaceuticals, which can help sustain weight loss, as well as surgical therapies for those patients whose weight is causing significant health problems. Physicians and other healthcare professionals should recognize that recidivism and failure is quite high with all of these therapies, and successful treatment will require a concerted effort on the part of physicians and other providers.
The following case study will be referenced throughout the text to illustrate the challenges of treating overweight/obese patients:
Patient B is a white woman, 52 years of age, with a history of type 2 diabetes mellitus, arthritis, hypertension, and hyperlipidemia who presents for a new patient evaluation. She is 5'2" and weighs 150 lbs. She is currently taking metformin, simvastatin, lisinopril, and celecoxib. On exam, her blood pressure is 150/92 mm Hg; heart rate 84 beats per minute; and respiration 16 breaths per minute. Laboratory analysis demonstrates blood glucose of 140 mg/dL; glycosylated hemoglobin 9.5%; cholesterol 205 mg/dL; low-density lipoprotein (LDL) 115 mg/dL; high-density lipoprotein (HDL) 52 mg/dL; and triglycerides 190 mg/dL. She asks for help in trying to lose weight. She expresses difficulty managing her weight since adolescence and has repeatedly cycled up and down with various fad diets and exercise programs. The patient states that she does not presently exercise because of arthritis in her knees and is confused about what she should or should not be eating. She wants to know if her weight really matters, because she knows plenty of people who are heavier than she and they seem to be fine. If it does matter, she wants to know what she should be doing.
The definition of obesity has been evolving over the past few decades. Historically, obesity has been defined simply as an excess of body fat . Today, however, measurement of body weight and height is most often utilized as a measure of obesity.
Initially, weight-for-height tables were used to determine the normal weight range for a given height. These tables were replaced with other indices when they were found to be of limited value due to their general estimates of frame size and bias toward the white population . These tables were replaced with the body mass index (BMI), which is calculated by weight in kg/height in meters2 or [weight (lbs)/height (inches)2] x 703. For most individuals, BMI correlates well with the proportion of body fat.
BMI is considered the general standard for defining obesity (Figure 1). An online BMI calculator is available at http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm.
In 1990, the U.S. Department of Health and Human Services' Dietary Guidelines for Americans defined overweight as a BMI of at least 27 and obesity as a BMI of at least 30. Eight years later, the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) released guidelines that lowered the cutoff for overweight to a BMI of 25, but maintained the definition of obesity as a BMI of at least 30 . (Note: Roughly, a BMI >25 corresponds to about 10% over one's ideal weight; a BMI >30 typically is an excess of 30 lbs for most people. These are rough estimates.) The term severe (or morbid) obesity refers to obesity with a BMI greater than or equal to 40. These final definitions are consistent with definitions used by other national and international organizations, such as the World Health Organization (WHO). Table 1 illustrates the similarities in the classifications used by the WHO and NHLBI.
BODY MASS INDEX CLASSIFICATION
|WHO Classification||BMI (kg/m2)|
|Obese Class I||30.0–34.9|
|Obese Class II||35.0–39.9|
|Obese Class III||>40.0|
|The additional classification of obesity (Class I–III) was used to determine if the prevalence rate for comorbidities vary with class range. In addition, the BMI classification used 5 BMI unit intervals to classify obesity rather than using a single cut-off value.|
These definitions are based on epidemiological evidence that suggests health risks are greater at or above a BMI of 25, compared to those below 25. The risk of death from all causes rises with increasing BMI, with a significant increase at BMI greater than 30. In a large cohort study published in the New England Journal of Medicine in 2006, persons with a BMI greater than 30 had mortality rates two to three times that of persons with BMI between 20 and 25 .
BMI does have limitations as a measurement of overweight and obesity. Although BMI provides a more accurate measure of total body fat compared with body weight alone, it can be misinterpreted in some circumstances. For instance, a muscled athlete would be considered overweight if BMI were used alone, despite his or her very low fat content. BMI can also underestimate body fat in persons who have lost muscle mass, such as elderly patients. Therefore, using other estimates, such as the triceps skinfold test, in addition to BMI may provide a better estimate of a patient's weight-related health status, especially in some atypical patients. (Note: There are various anatomical sites around the body that may be used for the triceps skinfold test, other than the triceps. The tester pinches the skin, raising only a double layer of skin and the underlying adipose tissue. The calipers are then applied 1 cm below and perpendicular to the pinch. Three readings are taken and then averaged to produce a final reading that is used in an equation to provide a more accurate estimate of body fat.) As a general reference, the U.S. Department of Defense states that the maximum allowable percent body fat of military personnel is 26% for men and 36% for women .
In defining obesity, NIH also identified excess fat in the abdomen out of proportion to total body fat as an independent predictor of risk factors and morbidity . The gender-specific cutoffs for waist circumference are as follows:
Men: >40 inches (102 cm)
Women: >35 inches (88 cm)
These are of value only for those with a BMI between 25.5 and 34.9. It is not useful to measure waist circumference in individuals with BMI >35, as such patients are already at increased risk.
In this example, Patient B's BMI is 27. Her waist circumference is 35.5 inches. Both of these measurements place her at increased risk for morbidity and death. Intervention should be made.
Within the past few decades, the prevalence of obesity has increased dramatically. In 1980, the percentage of obese and severely obese adults was 15% and 1.4% of the total population, respectively; by 1994, the numbers had increased to 23.2% and 3.0% . In the year 2000, 30.9% of the adult population was obese and 5.0% were severely obese . Data collected in 2013–2014 show that 37.7% are obese and 7.7% are severely obese (class III); an additional 33.3% of adults are overweight [1,75]. That means that more than 70% of Americans 20 years of age or older are above a healthy weight and are at an increased risk for disease and early death.
With race/ethnic origin not factored, the prevalence of overweight is higher for men (37.3%) than for women (29.5%), but rates of obesity and severe obesity are higher among women . In the overall population, 35.0% of men and 40.4% of women are obese, and approximately 5.5% of men and 9.9% of women have class III obesity .
When considered as a single race, the prevalence of obesity among individuals of African (48.4%) and Hispanic (42.6%) descent is greater than that reported for adults of European or Caucasian (36.4%) descent . Native American/Alaska Natives and Native Hawaiian/Pacific Islanders have an obesity prevalence of 41.2% and 38.3%, respectively . Asian Americans are an exception, with a prevalence of 12.6%, much lower than in the general population. Although the rate of obesity is higher in many American racial/ethnic groups compared to non-Hispanic whites, white individuals make up the majority of cases (50.2 million out of 78.6 million total cases) .
Obesity is most common among individuals 40 to 59 years of age, with 41% of American men and women in this age group fitting this description . However, roughly 57.5% of African American women and 51.1% of Hispanic women in this age group are obese . There is also a higher incidence of obesity (greater in women than in men) with lower socioeconomic status among all races .
Of particular concern is the increase in the number of children who have high BMIs. Presently, nearly 9% of children 2 to 5 years of age, 17.5% of children 6 to 11 years of age, and 20.5% of adolescents between 12 to 19 years of age are obese . The prevalence of obesity in adolescents has more than quadrupled since 1980 . This is especially troubling because overweight adolescents have a 70% chance of becoming overweight or obese adults; if their parents are overweight or obese, this chance increases to 80% .
The impact of obesity on general health is significant. A BMI of 35 or greater increases mortality 40% for women and 62% for men, and obesity in general results in an estimated 100,000 to 300,000 preventable deaths per year [7,8]. Preventable deaths attributable to poor diet and inactivity are second only to deaths due to tobacco use, but as cigarette smoking has declined, preventable deaths attributable to obesity-related conditions are set to overtake tobacco-related deaths . The economic costs are significant as well, with the total annual costs of obesity estimated to be $147 billion [5,16]. Roughly 10% of the nation's healthcare expenses are obesity-related, and this is expected to increase to between 16% and 18% by 2030 [5,102].
As noted, although the impact of obesity on general health has become highly publicized, most overweight Americans do not consider themselves at higher risk for medical problems or premature death. According to the results of a survey conducted by Shape Up America, 7 out of 10 overweight respondents said that their excess pounds were not a health concern. However, the survey results indicated that approximately 33% of the respondents had already developed a weight-related medical condition . Despite the evidence linking obesity and poor health, many Americans still consider excess weight to be only a cosmetic issue. This is in light of the fact that more than 80% of patients with diabetes are overweight or obese .
One of the most common, but oversimplified, explanations for obesity is that it is merely the result of sustained caloric imbalance. Caloric imbalance can be caused by either excessive intake of energy or decreased energy expenditure. With the increased availability of foods with poor nutrition content and decreasing desire for an active lifestyle, the resulting obesity is unsurprising. The cultural evolutionary explanation of obesity argues that our species evolved in an environment where food was often scarce, so our bodies developed an "evolutionary predisposition to store energy in the form of fat" in preparation for those shortages .
Though the scientific community has been unable to identify a single etiological agent for obesity, there have been clinical advances in the past decade. Obesity is known to be associated with certain exogenous causes. Genetic factors gained national attention after the discovery of leptin in 1995 by positional cloning in the leptin-deficient mouse model of obesity . Leptin (derived from the Greek word leptos, meaning "thin") is a 16-kilodalton adipocyte-derived hormone from the ob gene and has been the focus of many genetic investigations to elucidate the pathophysiology of obesity. Though this finding is relatively recent, its existence was suspected twenty years ago. In 1978, Coleman proposed that a circulating factor in the plasma of the db mouse strain, which is both diabetic and obese, could reduce the obesity of the ob mouse (a strain of mice with mutations in leptin) . The db mice were found to have mutations in the leptin receptor and were subsequently resistant to the leptin, unlike the ob mice who possessed a mutated leptin gene but functional leptin receptors. Further investigations revealed that injections of leptin in ob mice could cure obesity and diabetes. After locating the human homologues to the leptin gene and its receptor in 1999, the chromosomal locus containing the leptin gene was determined to be genetically related to human body weight . However, only a few people with mutated leptin genes have been identified, while the majority of obese patients have fully functional leptin genes and receptors.
Genetic diseases with associated obesity include Schinzel Syndrome, Bardet-Biedel Syndrome, Albright Hereditary Osteodystrophy, and Prader-Willi Syndrome. Many of these genetic disorders present with dysmorphic features, developmental delay, and obesity in addition to changes seen specifically with each disorder . For instance, young males with Prader-Willi Syndrome present with the features described above as well as with linear growth defects and undescended testicles.
Overall, the relationship between genetics and obesity cannot be fully determined at this time. Evidence suggests a link between the two, implying that genetics is one of the complex factors involved in the development of this prevalent condition. Although many argue that "obesity genes" cannot be responsible for the epidemic, because the gene pool in the United States had not changed significantly between 1980 and 1994, the etiology of obesity is most likely multifactorial . In 2010, one group of researchers confirmed 14 genetic variations and discovered an additional 18 variations associated with obesity . Further research is needed to clarify the influence of genetics.
Biological factors must also be considered. Proteins and receptors appear to have a role in weight control. For example, orexin A and B are located in the lateral hypothalamus, an area which may regulate body weight. Ongoing research may help determine the role of orexin in obesity.
Environmental factors seem to play a significant role as well. Data from a longitudinal twin-family study and co-twin control studies combined with population-based data on patterns of dietary intake and physical activity provide some evidence that environment can contribute to obesity . Some theorize that obesity is self-fulfilling in that if an individual is told they are predisposed to becoming fat, he or she will decide there is no point in eating healthy or exercising .
Occasionally, obesity is due to endocrinological origins from hypothyroidism or Cushing's syndrome. However, both of these conditions, along with other diseases associated with obesity, present with additional signs and symptoms. Moreover, they typically have appropriate treatment regimens that address the underlying cause of the obesity.
Given the influence of genetic and environmental factors, the issue of obesity cannot be simplified to sustained caloric imbalance. There are complex metabolic, psychological, endocrinological, social, and cultural influences regulating energy intake and energy expenditure, which indicates that obesity is more than a lack of self-control when presented with food.
Coronary heart disease
Type 2 diabetes
Colon, breast, endometrial, and possibly other cancers
In the Nurses' Health Study (a large prospective cohort study involving more than 100,000 women), women older than 35 years with a BMI greater than 27 were found to have an increased risk for cancer, heart disease, and other diseases. For instance, women gaining more than 20 pounds (9 kg) between 18 and 35 years of age doubled their risk for breast cancer compared with women who maintained their weight . Additionally, the age and smoking-adjusted relative risk of non-fatal myocardial infarction and fatal coronary disease for women with BMI 25 to 29 was 1.8; for women with BMI greater than 29, it was 3.3.
Left ventricular hypertrophy (LVH) is often seen in obese patients and correlates to the resulting systemic hypertension . The risk for type 2 diabetes has been reported to be twofold in the mildly obese, fivefold in moderately obese, and tenfold in severely obese persons .
In one study, individuals with a BMI of at least 30 had an elevated risk of pancreatic cancer compared to those with a BMI of less than 23 . A study published in 2012 involving 720,000 men found that overweight adolescents had more than double the risk of developing pancreatic cancer as young or middle-age adults compared to normal weight individuals . In general, obese patients showed an increased risk of 5.4 times that of non-obese patients for endometrial cancer, 3.6 times for gallbladder cancer, 2.4 times for cervical cancer, 1.6 times for ovarian cancer, 1.5 times for breast cancer, 1.7 times for colorectal cancer, and 1.3 times for prostate cancer . Cancer mortality is also increased in obese patients.
The term "metabolic syndrome" has been used when three or more of the following risk factors are present:
Abdominal obesity: waist circumference >40 inches in men or >35 inches in women
Triglycerides >150 mg/dL
HDL <40 mg/dL in men, <50 mg/dL in women
Blood pressure >130 / >85 mm Hg
Fasting glucose >110 mg/dL or 2-hour post glucose challenge >140 mg/dL
The development of this metabolic disorder is promoted by excess body fat and physical inactivity. It is believed to predispose patients to heart disease, cerebrovascular disease, and diabetes due to the associated dyslipidemia, hypertension, glucose intolerance, and hypercoagulability. Reduction in body weight and body fat through exercise also improves glycemic control and reduces the complications of diabetes .
One can stratify overweight and obese patients to determine their absolute risk by incorporating the presence of comorbidities and cardiovascular disease risk factors. Patients with coronary heart disease, other atherosclerotic diseases, type 2 diabetes, and sleep apnea are at "very high risk" for death; in comparison, those with three or more cardiovascular risk factors are at the "highest absolute risk." (Note: These risk factors include hypertension, hypercholesterolemia, smoking, family history of early heart disease, and age [men older than 45 years of age, women older than 55 years of age].)
Conditions that are associated with obesity usually worsen as the degree of obesity increases. For instance, one study showed that the risk of developing dementia increases 3.6 times in individuals with high BMIs (particularly in individuals with both high BMI and abdominal obesity) . Moreover, individuals' health typically improves and risk factors lessen as obesity is successfully treated. In addition, overweight and obese patients often suffer from emotional distress and face discrimination in their personal and professional lives. Many overweight patients suffer from social stigmatization and isolation, which subsequently increases morbidity and mortality. In one study, 13% of all women reported delaying or canceling a doctor's appointment because of concerns about their weight (e.g., embarrassment, fear of a lecture), while 32% of those with BMI greater than 27 and 55% with BMI greater than 35 had done the same .
Patient B has several comorbidities, including diabetes, dyslipidemia, hypertension, and osteoarthritis. She is at "very high risk" for premature death. Most of these conditions would improve if her weight were reduced.
The goal of therapy is to reduce body weight as well as body fat and maintain a lower body weight for the long term. The rate of weight loss should be 1 to 2 lbs per week, with a goal of 10% weight loss over 6 months. It is important to note that weight loss as modest as 10 lbs reduces the risk factors for several diseases. Such weight loss can lower blood pressure, lower blood sugar, reduce inflammation, and improve lipid levels. Unfortunately, most patients believe a weight loss of 30 to 40 lbs is necessary to medically benefit and become discouraged when they do not see such results . Patients should set realistic expectations from the start, with the idea that small losses of 10 lbs can be considered successes. Moreover, physicians must emphasize the importance of long-term weight management and weight loss rather than short-term extreme weight reduction.
Of note, weight reduction treatment is not recommended for pregnant women or for patients with unstable mental or medical conditions. Patients with terminal illness may also be excluded from treatment.
Before any treatment plan is attempted, one must assess the patient's willingness and motivation. If a patient is not willing to attempt weight loss, despite the risks as well as existence of current medical problems, treatment will be unsuccessful. Patients cannot be forced to lose weight, nor can they be berated or shamed into doing it. A productive dialogue focusing on the patient's goals and the health risks of being overweight will be the most successful.
Patient B clearly is seeking guidance. She is interested in a treatment plan and illustrates this by seeking additional information despite her failure at past attempts. She must realize that her weight really does matter and indeed is already contributing to her morbidity. Her medical conditions are stable. She is eligible and ready for treatment.
The 10-step approach, as shown in Table 2, is recommended by the National Institutes of Health (NIH) in developing an assessment and treatment plan.
Ten Steps to Treating Overweight and Obesity in the Primary Care Setting
The treatment of obesity includes three types of therapies:
Behavioral therapy includes a combination of diet and exercise and is the cornerstone of any weight reduction treatment. Diet and exercise remain a significant challenge for most adults, as evidenced by the number of overweight and obese people. Most adults do not eat nutritiously and do not exercise regularly. About 25% of adults report engaging in no physical activity at all in the past month . NHIS data shows 62% of adults engaging in no vigorous physical activity during leisure time and only 24% getting regular exercise three or more times a week .
Reviewing and modifying diet is one of the most important steps in helping patients lose weight. As a simple rule, caloric intake should be reduced by 500–1000 calories per day from a patient's current level. Patients with a BMI of 27–35 should reduce total calories by 300–500 daily; patients with BMI greater than 35 should reduce total calories by 500–1000 daily. This reduction will produce the recommended weight loss of 1–2 lbs per week in most patients. The recommended number of total calories will vary depending upon activity level: 1600 calories for most sedentary women, 2200 calories for sedentary men or active women, 2600 calories for active men. To calculate specific caloric requirements, the following approach is useful:
First calculate resting energy expenditure (REE).
For men: (10 x weight (kg)) + (6.25 x height (cm)) - (5 x age + 5)
For women: (10 x weight (kg)) + (6.25 x height (cm)) - (5 x age -161)
Multiply REE by activity factor (AF).
For light activity, AF is 1.5 for women, 1.6 for men. For high activity, AF is 1.6 for women, 1.7 for men.
In terms of diet specifics, conflicting information exists. Many newspapers and magazines offer detailed articles addressing the successes of individual patients on the Atkins diet, the Ornish plan, the Zone diet, the Body-for-Life program, and others (Table 3). Differences among these diets leave patients confused and discouraged. The Internet compounds the confusion by providing unfiltered information and a lack of emphasis on current research and evidence-based medicine.
VARIOUS POPULAR DIETS
|Breakdown||High fat (55% to 65%) Low carbs (<100 g/day)||High complex carbs Low fat (<10%) Vegetarian||40% carbs 30% protein 30% fat||High protein, moderate carbs, low fat all eaten at same time, with small, frequent meals.|
|Mechanism of Action||Reducing carbohydrates causes ketosis, which induces use of excess body fat for fuel||Reduction in total calories and total fat||Reduction in total calories causes weight loss||More steady release of insulin causes less fat deposition.|
There has been some progress in assessing these various diets, but without strong evidence in favor of any particular one. In 2003, a study conducted at the University of Pennsylvania, supported by the NIH, concluded that the Atkins diet resulted in greater weight loss (approximately 4%) at the end of one year, as well as an improvement in some cardiovascular risk factors . In 2005, researchers at Tufts University compared the Atkins, Ornish, Weight Watchers and Zone diets, with weight reduction and cardiovascular disease reduction as outcomes. (The Atkins diet restricts carbohydrates, the Zone diet involves balancing macronutrient intake, the Ornish diet restricts fat, and the Weight Watchers diet restricts calories.) After one year, all diets produced moderate weight loss and improvement in HDL, C-reactive protein, and insulin levels. Increased adherence to each diet was associated with increased weight loss, but overall adherence was low . In 2007, researchers reported on a randomized trial of the Zone, Atkins, Ornish, and LEARN diets in 311 overweight or obese non-diabetic, premenopausal women. (The LEARN diet is based on national nutrition guidelines.) Again, all diets provided modest weight loss at one year. The Atkins diet produced the most weight loss, with improvements in cardiovascular risk factors that were comparable to or better than the other diets. However, weight loss trajectories had not stabilized at the end of the study, suggesting that longer observation might produce different outcomes . For each diet plan, larger and longer studies are necessary to assess long-term benefits and risks.
It is important that any diet contain food from all food groups, so that it remains nutritionally adequate. "Fad diets" typically have nutritional deficiencies, and this is one reason why they are potentially dangerous. For example, high-fat, low-carbohydrate diets are low in vitamins E and A, thiamin, folate, calcium, magnesium, and zinc. Low-fat diets are typically deficient in vitamin B12.
Instead of recommending a specific type of diet, physicians should encourage patients to focus on well-balanced meals from the various food groups. Recommendations from the Institute of Medicine provide a useful framework, as do the Dietary Guidelines for Americans.
In 2005, the IOM issued its first volume in a series of reports that suggest dietary reference values for intake of nutrients. This project was released by the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes of the Food and Nutrition Board from the Institute of Medicine, a division of the National Academies. The report establishes the Dietary Reference Intakes (DRIs) for energy and macronutrients: carbohydrates, fiber, fat, fatty acids, cholesterol, protein, and amino acids. A synopsis of the main findings follows. The full report, with the detailed rationale used to establish each guideline/recommendation, can be accessed online at http://www.nap.edu/openbook.php?isbn=0309085373.
The following ranges are recommended for percentage of daily caloric intake :
Carbohydrates: 45% to 65%
Fats: 20% to 35%
Protein: 10% to 35% (dietary protein should be 0.8 g/kg/day)
Men younger than 50 years of age: 38 grams per day
Women younger than 50 years of age: 25 grams per day
Men older than 50 years of age: 30 grams per day
Women older than 50 years of age: 21 grams per day–
The report distinguishes the different types of fat. Saturated fat and trans fatty acids typically raise the amount of LDL in the bloodstream. Because this type of fat has little value, there is no recommended intake requirement, and people should be advised to keep consumption as low as possible. Sources include meat, poultry, baked goods, and dairy products, as well as some vegetable sources, such as coconut and palm oils.
In contrast to saturated fat, monounsaturated and polyunsaturated fat reduce blood cholesterol levels. As much as possible, one should replace saturated fat with unsaturated fat. Two types of polyunsaturated fat are critical elements of a healthy diet because they are not synthesized in the body. These are omega-3 and omega-6. Omega-3, or alpha-linolenic acid, consumption should be 1.6 g for men and 1.1 g for women; omega-6, or linoleic acid, consumption should be 17 g for men and 12 g for women daily. Sources of monounsaturated fat include plants, peanuts, avocado, and canola oil. Sources of polyunsaturated fat include safflower, sunflower, corn, and soybean oils. Omega-3 fatty acids are found in oily fish and flaxseed.
An interactive dietary reference intake calculator is available at http://fnic.nal.usda.gov/fnic/interactiveDRI. Height, weight, age, and activity level are inputted into the calculator, and a complete individualized profile of caloric needs—plus vitamin, mineral, and water intake—is outputted for the patient.
The 2010 Dietary Guidelines for Americans recommends a "healthy eating pattern [that] limits intake of sodium, solid fats, added sugars, and refined grains and emphasizes nutrient-dense foods and beverages—vegetables, fruits, whole grains, fat-free or low-fat milk and milk products, seafood, lean meats and poultry, eggs, beans and peas, and nuts and seeds" . Decreased caloric intake with increased exercise is suggested for people who need to lose weight, with the goal of slow and steady weight loss over time.
Specific recommendations for adults, based on a "reference diet" of 2,000 calories per day, include :
Two cups of fruit and 2½ cups of vegetables per day, with an emphasis on high-fiber choices; weekly recommendations are 1½ cups/week of dark green vegetables, 5½ cups/week of red/orange vegetables, 1½ cups/week of beans and peas, 5 cups/ week of starchy vegetables, and 4 cups/ week of other vegetables
3 or more ounce-equivalents of whole-grain products per day, with at least half of all grain products consumed coming from whole grains
3 cups per day of fat-free or low-fat milk or equivalent milk products
8 ounces of seafood per week
Less than 10% of calories from saturated fats, with as few trans fats as possible and total fat intake between 20% and 35% of calories
Less than 300 mg/day of cholesterol per day
Less than 2,300 mg (approximately 1 tsp of salt) of sodium per day for individuals 50 years of age and younger; less than 1,500 mg of sodium per day for individuals who are older than 50 years of age, are of African descent, and/or have diabetes, hypertension, or chronic kidney disease
The USDA's MyPlate plan and the DASH diet both fulfill the Guidelines' recommendations. MyPlate is an individualized guide for healthy eating based on age, sex, height, weight, and physical activity level. Patients can create their own MyPlate plans at http://www.choosemyplate.gov. The DASH diet (Dietary Approaches to Stop Hypertension) was originally developed as a method to prevent and treat hypertension, but it provides a balanced diet that is appropriate for most adults. Patient-friendly information about the DASH diet is available at http://www.nhlbi.nih.gov/health/health-topics/topics/dash.
Patients must keep in mind that as they change their diet and begin to lose body weight, body fat and lean body mass also decrease. The optimal goal of therapy is to maximize loss of body fat and minimize loss of lean body mass.
Exercise increases energy expenditure, and regular physical exercise is an important predictor of long-term weight maintenance. It is as important as diet, and patients should understand this point. Several studies have shown that patients who diet and exercise regularly are much more likely to maintain weight loss than those who simply change their diet. Multiple studies have demonstrated that a program of diet and exercise can reduce the number of persons who progress from impaired glucose tolerance to frank diabetes by 50% or more [37,38,39,40].
As noted earlier, approximately 25% of American adults rarely (or never) exercise. There are numerous reasons for this, including lack of interest, competing demands for leisure time, lack of knowledge of proper technique, and fear of injury. Compounding this problem, in a 2001 survey, it was found that only 28% of subjects reported receiving advice from their physicians to increase their physical activity . Of the individuals who received advice, only 38% (or 11% total group) received help formulating a specific activity plan, and 42% received follow-up support.
According to the CDC, adults should engage in at least 150 minutes of moderate-intensity aerobic activity (e.g., brisk walking) or 75 minutes/week of vigorous-intensity exercise (e.g., jogging, running) every week, combined with muscle-strengthening activities that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms) 2 or more days per week for moderate health benefits . (Note: A weekly workout can include a mix of exercise intensity equal to the given recommendations.) For increased health benefits, moderate-intensity aerobic exercise should be doubled to 300 minutes per week .
The 2010 Dietary Guidelines for Americans include recommendations for physical activity similar to the CDC recommendations [70,83]. It should be emphasized that usual daily activities at work or around the house should not be counted towards patients' exercise goals, but that these should continue in addition to exercise. Patients should be advised that exercise activities can begin at 10 minutes per day and slowly increase. Many individuals will need to exercise in excess of 300 minutes per week to achieve and maintain weight loss and to improve medical conditions .
In 2007, the American Heart Association (AHA) released new guidelines for physical activity, in partnership with the American College of Sports Medicine (ACSM) . The new guidelines are intended to clarify recommendations originally released in 1995 by the ACSM and the CDC. For healthy adults 18 to 65 years of age, the AHA and ACSM recommend:
Moderate-intensity aerobic activity on 5 days per week for 30 minutes or more, or vigorous-intensity aerobic activity on 3 days per week for 20 minutes or more.
Resistance or strength training, or activity that improves strength and endurance, at least twice a week.
Vigorous-and moderate-intensity activity can be combined to meet the goals. For example, a brisk half-hour walk twice a week plus a 20-minute jog twice a week fulfills the recommendations. Moderate-intensity bouts of exercise lasting at least ten minutes can be added together over the course of a day. Activities of daily living, such as household chores, do not count toward the goals.
Strength training should include 8 to 10 exercises using the major muscle groups on two or more non-consecutive days. Weights should allow 8 to 12 repetitions before fatigue.
The AHA and ACSM also offer specific recommendations for older adults . Aerobic and strength training goals are the same, although the guidelines note that the same exercise may be "moderate" for some older adults and "vigorous" for others, depending on baseline fitness level. Additional recommendations include:
Exercises to promote flexibility, for at least 10 minutes two days a week.
Balance-improving exercises for adults at risk of falls.
Integration of preventive and therapeutic recommendations, so as to accommodate illness or restrictions on movement while avoiding a sedentary lifestyle.
The key is to make physical activity a part of everyday life by encouraging patients to choose activities of interest. Exercise should not be a chore, but rather an enjoyable activity that people look forward to. This may be light jogging, dancing, vigorous walking, or perhaps swimming for patients with arthritis. Patients should be encouraged to surround themselves with people supportive of exercise, who may join them in this activity. Patients should also consider varying their routine so they do not get bored. One study demonstrated that women older than 50 years of age who spent approximately 2.5 hours per week walking briskly reduced their risk of cardiovascular disease by 30% . For patients with chronic renal insufficiency, resistance training has been shown to be effective against the catabolism of a low-protein diet and uremia .
It is also recommended that patients self-monitor. This entails keeping a diary of caloric intake and physical activity. Such a log encourages adherence, and most patients can see some success by noting their daily progress over time. They should bring this log to each visit, which should be 1 to 2 times per month early on. Physicians should review this diary with patients to ensure that they are properly following a structured program. Some patients will need closer monitoring, depending on cardiac risk and the presence of other medical conditions.
Although behavioral strategies can be effective, weight regain is common. Patients typically regain weight after leaving a structured program. Patients must understand that these changes must become their daily lives. They should change slowly, choosing foods and activities they can enjoy. They need to understand that occasional setbacks may occur, and that instead of becoming frustrated they should try to remain focused on long-term goals. Permanent lifestyle changes remain one of the most difficult interventions to implement. Patients need support, positive feedback, continual encouragement, and reinforcement.
Patient B should be counseled to adopt a diet and exercise regimen. She needs to decrease her calories by 500 calories per day and distribute her calories to 45% to 65% carbohydrates, 25% sugar or less, 20% to 35% fat, and 10% to 35% protein. She should choose an exercise program she enjoys — perhaps swimming, which would not only cause less stress on her joints but may also improve her arthritis. She should start slowly, 10 to 20 minutes several times a week, gradually building up to one hour, 5 or more times a week.
Pharmacotherapy should only be used as an adjunct to behavioral interventions. It should not be used as a primary treatment option or by people who are unwilling to make behavioral changes. Rather, if lifestyle changes do not promote weight loss after 6 months, drugs should be considered.
Most weight-loss agents suppress appetite or block pancreatic lipase. Presently, five drugs (orlistat, lorcaserin, phentermine/topiramate, liraglutide, and bupropion/naltrexone) are approved by the U.S. Food and Drug Administration (FDA) for long-term weight loss. Orlistat is available by prescription (brand name Xenical) or over-the-counter (brand name Alli). Lorcaserin (brand name Belviq), phentermine/topiramate (brand name Qsymia), liraglutide (brant name Saxenda), and bupropion/naltrexone (brand name Contrave) are available by prescription only.
Orlistat is a pancreatic lipase inhibitor. It causes weight loss by blocking absorption of up to one-third of ingested fat. It is typically used with a reduced calorie diet with about 30% of calories from fat. Because absorption of fat-soluble vitamins can be affected, patients are advised to take a multivitamin daily. Several clinical studies have shown that when orlistat is combined with a low-calorie, low-fat diet, it increases weight loss compared with a placebo and low-calorie, low-fat diet. For example, in a randomized controlled trial conducted in Europe, patients using orlistat and eating a low-fat diet experienced a weight loss of 10.2% compared to 6.1% in the control group at one year . In this study, total cholesterol, LDL, LDL/HDL ratio, and glucose showed a significant reduction. At year two, patients who continued with orlistat regained half as much weight as those patients who switched to placebo. In another randomized trial, patients using orlistat with a low-calorie diet experienced a loss of 8.5% of their initial body weight, compared with 5.4% in the placebo group . Moreover, 35% of patients using orlistat lost at least 5% of body weight, compared with 21% in the placebo group; 28% lost 10% of body weight compared with 17% in control group. In a randomized controlled trial conducted in the United States, patients treated with orlistat lost an average of 15 lbs versus 8 lbs in the control group . More patients in the experimental group lost 5% of initial weight than those in the control group, and 34% of patients using orlistat sustained the weight loss at 2 years versus 24% in the control group.
Orlistat is contraindicated in patients with chronic malabsorption syndrome or cholestasis, and it should be used with caution in patients taking cyclosporine. Side effects of orlistat include, but are not limited to, increased fecal fat loss, incontinence, and diarrhea. Dietary supplementation with fat-soluble vitamins is recommended. Rarely, patients taking orlistat have developed severe liver injury, and this risk should be weighed against potential benefits .
In 2012, the FDA approved both lorcaserin and phentermine/topiramate, the first new weight-loss medications in more than a decade [95,98]. Lorcaserin is a selective 5-HT2C receptor agonist and acts to promote weight loss by giving the patient a feeling of satiety . Trials indicate that lorcaserin is safe and effective treatment, in conjunction with diet modification and exercise, for adults with a BMI ≥30 or adults with a BMI ≥27 with at least one weight-related comorbidity (e.g., hypertension, dyslipidemia, sleep apnea). In a multicenter, placebo-controlled trial involving 3,182 obese patients (mean BMI: 36.2), researchers assessed the efficacy and safety of the drug in obese adults . More individuals in the lorcaserin treatment group (47.5%) lost at least 5% of their baseline weight after 1 year, significantly more than in the placebo group (20.3%). In addition, patients who continued to take lorcaserin in the second year were more likely to maintain their weight loss than those who switched to placebo. These finding were replicated in the Behavioral modification and Lorcaserin for Overweight and Obesity Management (BLOOM) trial, which found that significantly more patients treated with lorcaserin lost at least 5% of baseline body weight compared with placebo .
The recommended dose of lorcaserin is 10 mg twice daily . Originally rejected, the manufacturer was required to submit additional safety data, specifically related to the risk for valvular heart disease, prior to approval . Data indicated that the risk of valvular heart disease was not higher with lorcaserin compared to placebo. Possible adverse effects include headache, nausea, and dizziness . Dropout rates in the clinical trials were similar in the treatment and placebo groups [96,97].
Phentermine/topiramate (extended-release) combines an anorexiant and an anticonvulsant to improve short-term weight-loss outcomes in patients who have already attempted lifestyle changes (i.e., calorie-restricted diet and increased physical activity) . As with lorcaserin, eligible patients will have a BMI ≥30 or a BMI ≥27 with a weight-related comorbidity . In two randomized, placebo-controlled trials involving approximately 3,700 obese and overweight patients, phentermine/topiramate was found to be effective and safe if used correctly . After one year, patients taking phentermine/topiramate experienced 6.7% (at the recommended dose) to 8.9% (at the highest dose) greater weight loss compared to those taking placebo. More than 60% of participants taking phentermine/topiramate recorded at least a 5% decrease in their body weight, compared to only 20% of the placebo group .
The recommended initial dose of phentermine/topiramate is 7.5 mg phentermine/46 mg topiramate extended-release once per day . The dose may be titrated to a maximum of 15 mg/92 mg. The medication is contraindicated in persons with glaucoma and hyperthyroidism and is not recommended for patients with a recent history of stroke or heart disease . It is also teratogenic, with proven fetal defects with first trimester exposure. Therefore, all women of childbearing age should use effective contraception consistently while taking the drug and have documented proof of a negative pregnancy test prior to the initiation of treatment and every month thereafter .
In 2014, combination bupropion/naltrexone was approved as a treatment option for chronic weight management . Studies show that these drugs are effective in improving the percentage of total body weight lost compared to placebo [84,99]. The dosage is gradually titrated up, starting with one tablet (naltrexone 8 mg/bupropion 90 mg) once daily in the morning for one week and increasing one daily tablet each week for four weeks. The maintenance dose is two tablets twice daily . If 5% of initial body weight has not been lost after 12 weeks, the medication should be discontinued.
Any patient taking bupropion should be carefully monitored for suicidal ideation and behaviors . This medication may also increase blood pressure and heart rate and is contraindicated in patients with hypertension. It is also contraindicated in patients with a history of seizures, who are taking another bupropion-containing medication, or who are pregnant.
Also in 2014, the GLP-1 receptor agonist liraglutide was approved by the FDA for chronic weight management. Traditionally used to treat diabetes, liraglutide has been found to aid in appetite suppression and weight loss . The dosage of liraglutide used for weight management (3 mg) differs from the dose used in diabetes medication regimens (1.8 mg), and the safety and efficacy of this higher dose for the treatment of diabetes has not been established . This medication is contraindicated in those with a personal or family history of thyroid cancer.
When pharmacotherapy is effective, weight loss should exceed 2 kg (4.4 lbs) during the first month and weight should decrease by about 5% of baseline within 6 months. Pharmacotherapy should be discontinued if weight loss is not achieved. When it is successful, pharmacotherapy with orlistat may be continued past one year; data is currently available to 4 years with orlistat . Patients should keep in mind that weight loss typically stabilizes after 6 months of treatment, and weight gain can occur when pharmacological therapy is discontinued.
Several drugs are approved for short-term use in obese patients. These include sympathomimetic agents such as benzphetamine, methamphetamine, phentermine, phendimetrazine, and diethylpropion . Data on long-term safety has not been demonstrated. Given that weight loss therapy is focused on long-term success, use of these drugs is rarely recommended. Leptin resistance may be a contributing factor to obesity in some cases, and leptin is being explored as a possible treatment.
The cannabinoid receptor antagonist rimonabant, which acts as an appetite suppressant, has shown promise for weight loss. It is currently available in Europe. However, the FDA declined to approve this drug for use in the United States, citing concerns about the risk-benefit profile and the need for more data. In the future, rimonabant or similar drugs may become available in the United States.
Until October 2010, another drug, sibutramine, was approved by the FDA for use in the long-term management of weight. Randomized controlled trials supported the efficacy of sibutramine for short-term weight loss; however, there was some concern regarding the cardiovascular risk profile associated with the medication [50,51,52]. Postmarketing data indicated that patients with existing cardiovascular disease on long-term sibutramine therapy had an increased risk of nonfatal myocardial infarction and stroke . As a result, the manufacturer (Abbott Laboratories) responded to an FDA request by voluntarily removing the agent from the U.S. market in 2010 .
Other previously available drugs included dexfenfluramine and fenfluramine. Both have been withdrawn from the market due to either increased risk of pulmonary arterial hypertension or valvular heart disease.
Bariatric surgery has become increasingly common over the past decade. In 1998, there were 13,386 procedures; by 2004, nearly 136,000 bariatric surgeries were performed [55,85]. Between 2012 and 2013, the number of procedures plateaued at roughly 175,000 per year . Only 1% of the severely obese population undergoes bariatric surgeries each year [85,86]. In 2008, 90.2% of bariatric surgeries were performed laparoscopically, compared to 20.1% in 2003. Surgical procedures for overweight and obese patients include:
Vertical banded gastroplasty
The American Society for Metabolic and Bariatric Surgery and the Society of American Gastrointestinal Endoscopic Surgeons have reaffirmed the 1991 National Institutes of Health guideline, which states that surgery is indicated for adult patients with a BMI greater than 40 or greater than 35 with significant comorbid conditions and who can demonstrate that dietary attempts at weight loss have failed [56,57]. Bariatric surgery for patients older than 60 years of age has typically not been recommended. Patients should be thoroughly screened for a willingness to make lifestyle changes, as well as for any psychological disorders that would impair a successful postoperative course. Surgical treatment is not a cosmetic procedure. It does not involve the removal of adipose tissue by suction or excisions; rather, it involves reducing the size of the stomach, with or without a degree of malabsorption.
In addition to those patients identified in the 1991 guideline, the Society of American Gastrointestinal Endoscopic Surgeons indicates that other well-selected patients may benefit from laparoscopic bariatric surgery :
Individuals with BMI 30–35
Patients older than 60 years of age
Adolescent bariatric surgery (in patients younger than 18 years of age) has been proven effective but should be performed in a specialty center. Patient selection criteria should be the same as used for adult bariatric surgery.
Research supports the effectiveness of bariatric surgery for weight loss; however, there are few studies with outcomes greater than 1 year . In the Swedish Obese Subjects (SOS) study, a large, prospective, controlled trial of bariatric surgery (fixed or variable banding, vertical banded gastroplasty, or gastric bypass), average weight loss in surgical patients was 16% at 10 years compared to a 1.6% weight gain in controls . A 2005 Cochrane Review, which included earlier SOS results as well as multiple other studies, noted that evidence was limited (largely due to study design), but that surgery appeared to be more effective than conventional treatment . A meta-analysis published in 2004 in JAMA concluded that mean excess weight loss was 61.2% for bariatric surgery patients, with some variation among types of surgery .
It also appears that weight loss following bariatric surgery may be more sustainable than weight loss by conventional means. While weight regain often occurs within a few months to years after behavioral or pharmacologic treatment, studies show that weight loss can be sustained for many years after surgery . A large, single-center follow-up study of laparoscopic adjustable gastric banding patients showed the band was intact in 78% of patients beyond the 10-year follow-up, with a mean excess weight loss of 47% . At the 16-year mark, patients had an excess weight loss of 62%. The authors of the study reviewed other literature and noted a similar substantial long-term weight loss with other bariatric surgeries as well.
Although bariatric surgery is not without risk, there is evidence that it can reduce overall morbidity and mortality in obese patients. In a cohort study comparing 1,035 bariatric surgery patients with 5,746 age-and gender-matched controls, the surgery patients had significant reductions in the risk of cardiovascular disease, cancer, endocrine disorders, infections, and psychiatric disorders. The relative risk of death was 89% lower in the surgery group . Another study compared 7925 gastric bypass subjects with community-based controls. Mortality was lower by 40% among the surgery patients. Although deaths from causes other than disease were higher in the surgery patients, deaths from diabetes, cardiovascular disease, and cancer were all substantially reduced . The SOS study, the only large, well-controlled prospective trial of bariatric surgery, found unadjusted overall mortality reduced by 31.6% .
Multiple studies of comorbid conditions that are common in obesity have shown improvement following bariatric surgery. A meta-analysis of bariatric surgery studies showed strong improvements in diabetes, hypertension, hyperlipidemia, and sleep apnea . According to results from the SOS study, some of the improvements in morbidity may decrease over time; however, longer observation and additional studies are needed to confirm long-term effects .
These procedures combine creation of small stomach pouches to restrict food intake and construction of bypasses of the duodenum and other segments of the small intestine to cause malabsorption. In the past, the most common gastric bypass operation was Roux-en-Y gastric bypass (RYGB), with biliopancreatic diversion performed less frequently . According to one report, in 2003–2004 more than 90% of the weight-loss surgeries performed in the United States involved the Roux-en-Y technique, even though this surgery required longer time in surgery, longer hospital stays, and a higher likelihood of requiring intensive care . However, the advent of newer and less invasive techniques have led to these surgeries falling out of favor. In 2013, the American Society for Metabolic and Bariatric Surgery estimated that only 34% of bariatric surgeries involved RYGB and 1% were biliopancreatic diversion . Today, sleeve gastrectomy is the most commonly performed procedure (42.1%) .
In the SOS study, the gastric bypass group lost the most weight, compared to banding and vertical banded gastroplasty; they were also more likely to have lost more than 5% of baseline body weight . A meta-analysis of multiple studies concluded that weight loss was about 61.6% with gastric bypass and 70.1% with biliopancreatic diversion, vs. 47.5% for gastric banding. However, these procedures also carry a higher risk of nutritional deficiency.
Although gastric sleeve procedures have become more common, 34% of bariatric surgeries performed in 2013 were RYGB procedures . In this procedure, a small stomach pouch, approximately 25–30 mL in size, is created by either stapling or vertical banding. This causes restriction in food intake, such that patients can only eat several bites as a meal. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the duodenum as well as the first portion of the jejunum. This causes reduced calorie and nutrient absorption, resulting in weight loss. Gastric bypass is usually done laparoscopically.
With this procedure, severe nutritional deficiencies can develop. For instance, patients are at risk to develop iron deficiency due to lack of food contact with gastric acid and consequent diminished conversion of iron. In addition, vitamin B12 deficiency may occur because food is not coming into contact with gastric intrinsic factor. Vitamin D and calcium absorption may be reduced because the duodenum and proximal jejunum, which are the sites of calcium absorption, are bypassed. Lifelong supplements of multivitamins, B12, iron, and calcium are mandatory following this procedure.
In the BPD and BPD/DS operations, portions of the stomach (approximately two-thirds) are removed. The small pouch that remains is connected directly to the final segment of the small intestine, completely bypassing both the duodenum and jejunum. Thus, the time that food mixes with digestive fluids is fairly brief.
In biliopancreatic diversion with duodenal switch the pyloric valve is kept intact, a portion of the duodenum is left in the digestive loop, and the final segment of the small intestine is connected after the duodenum. Additionally, the upper end of the bypassed segment of the small intestine is attached to the pancreas and is joined at the final, common segment. The gallbladder may or may not be removed.
Restrictive procedures reduce the size of the stomach without interfering with absorption of food. Food intake is restricted by creating a small pouch at the top of the stomach where the food enters from the esophagus. The pouch initially holds about 1 ounce of food and can expand to 2 to 3 ounces over time. The pouch's lower outlet usually has a diameter of about ¼ inch. The small outlet delays the emptying of food from the pouch and causes a feeling of fullness. It does not otherwise alter the digestive tract. Restriction operations are intended to reduce the amount of food a patient can comfortably eat, thus reducing total caloric intake. The two most common restriction operations are gastric banding and vertical banded gastroplasty.
In this procedure, a band is placed around the stomach near its upper end, creating a small pouch and a narrow passage into the larger remainder of the stomach. An inflatable, adjustable ring controls the flow of food from the smaller pouch to the rest of the digestive tract. The patient will feel comfortably full with a small amount of food. Because of the slower emptying, the patient continues to feel full for several hours, thereby reducing the urge to eat between meals.
Although excess weight loss with this procedure is not as rapid as with other procedures (e.g., RYGB), long-term weight loss may be comparable for some patients [90,91]. One study found that weight loss percentages for RYGB and LGB were 35% and 19% after 3 months; 49% and 25% after 6 months; 64% and 36% after 1 year; and 60% and 57% after 3 years . However, other studies report that about half of LGB procedures result in inadequate weight loss . A 2008 systematic review noted that complication and short-term morbidity rates of LGB are lower than those of laparoscopic RYGB; however, reoperation rates with LGB are higher . This review noted that the highest quality study showed an excess weight loss percentage at 1 year of 48% for LGB, compared with 76% for RYGB.
It appears that LGB has quickly fallen out of favor. LGB accounted for 36% of bariatric procedures in 2011 but only 14% in 2013 .
In this procedure, both a band and staples are used to create a small pouch in the upper stomach with a narrow outlet reinforced by a mesh band to prevent stretching. After the procedure, the person usually can eat only a half to a whole cup of food without discomfort or nausea. Food must be well chewed. VBG, formerly one of the most common bariatric surgeries, is used less often now due to unsatisfactory weight loss results . Complications from the restriction can include vomiting, gastroesophageal reflux, and erosion of the band into the gastric tissue.
Neither of these procedures involves any anastomosis of the stomach or intestine, nor is there repositioning of the stomach or intestines. Intake becomes a function of a patient's ability to chew thoroughly and eat slowly. Failure to do so can result in repeated vomiting and isolated cases of nutritional deficiency.
Similar to the first step of BPD, laparoscopic sleeve gastrectomy (LSG) involves subtotal gastric resection, leaving a small, tubular stomach . Because the fundus of the stomach contains the cells that produce ghrelin (a hormone involved in regulation of food intake), removal of the fundus may contribute to weight loss beyond simple restriction. LSG is generally done in select obese and super-obese (BMI greater than 50) patients and followed, once weight is somewhat reduced, by completion of a RYGB or either of the BPD surgeries. Advantages of this approach include simplicity, low complication rates, no nutritional deficiencies, and no "dumping syndrome" .
A 2009 study of 135 patients who underwent the procedure (mean BMI: 48.8; range: 37–72) found that the average excess weight loss at 1 year was 49.4% . Complication rates were low, and none of the patients required conversion to laparotomy.
A 2010 review of 100 LSG patients (BMI greater than 40 or greater than 35 with severe comorbidity) found that the average excess weight loss was 49.1% at 6 months . There was also significant resolution of diabetes (46%), hypertension (38%), and hyperlipidemia (19%). The authors of the study recommend LSG as a single-step procedure, with no revision to RYGB or BPD, and LSG over gastric banding due to equivalent weight reduction and better tolerance.
Bariatric surgery does have complications. Approximately 10% to 20% of all patients who have weight-loss surgery require follow-up operations. Gastric bypass operations may cause "dumping syndrome," whereby stomach contents move too rapidly through the small intestine. Typically, this is caused by the high osmolarity of simple carbohydrates in the intestine. The higher concentration causes fluids to shift towards the higher osmolarity. This results in additional fluid in the bowel, which causes it to be stretched, with subsequent pain and nausea. Activation of hormonal and nerve responses causes increased heart rate. There may be vomiting and diarrhea. A short time later, there typically is a glucose spike, as the small bowel absorbs sugar. The pancreas responds by secreting insulin, which then causes hypoglycemia, causing weakness and light-headedness. Dumping syndrome should be monitored carefully.
Abdominal hernias can also occur, requiring follow-up surgery. More than one-third of obese patients who have gastric surgery develop gallstones. Post-operative complications may include deep vein thrombosis, pulmonary emboli, bleeding, band migration, and infection. Possible later complications include breakdown of the staple line or band erosion, causing internal infections.
Depending on the type of procedure, nearly 30% of patients who have weight-loss surgery can develop nutritional deficiencies such as anemia, osteoporosis, and metabolic bone disease. Therefore, it is important that patients take supplemental vitamins and minerals.
Because bariatric surgical procedures are still evolving, true surgical mortality rates are uncertain. The overall risk of death from gastric bypass appears to be less than 0.2% at 30 days and varies by the type of procedure . Older data, gathered between 1987 and 2001, suggested a 30-day mortality rate as high as 1.9%, but outcomes have improved as surgeons gained experience and more lower-risk patients sought treatment . The increase in laparoscopic procedures has contributed to a lower risk of death. It is estimated that the 30-day mortality rate is 0.14% for laparoscopic gastric bypass, 0.08% for laparoscopic sleeve gastrectomy, and 0.03% for laparoscopic gastric banding .
The appropriate surgery depends on a number of factors, including the skill of the surgeon and patient preference. Typically, restriction operations create slower and steadier weight loss than the bypass operations, which often show rapid weight loss in the first few months, stabilizing a year after surgery. With restriction operations, weight loss is typically 1 to 2 pounds per week, continuing on average for two years. However, restriction operations have higher potential for nutritional deficiency.
Bariatric surgery will not work for all patients. Between 10% and 50% of surgical subjects will not succeed with long-term weight loss [55,92]. Ongoing follow-up is an essential part of treatment, to watch for complications and encourage ongoing weight loss efforts.
The intragastric balloon is not yet available in the United States. Intended as a minimally invasive, short-term treatment, this procedure involves placement in the stomach of an inflatable, free-floating balloon. It may have indications for moderate obesity and for morbidly obese patients who need to lose weight before bariatric surgery. A 2007 Cochrane Review suggests that intragastric balloon treatment may not provide benefits over conventional therapy. However, evidence was limited and different trials used different techniques and clinical considerations .
Gastric stimulation is an experimental technique involving an implanted device similar to a cardiac pacemaker. Controllable from outside the body, the gastric stimulator is intended to reduce caloric intake . Vagus nerve therapy also involves the implantation of an electrical device with leads that directly stimulate the vagus nerve to control appetite.
As a result of the evolving racial and immigration demographics in the United States, interaction with patients for whom English is not a native language is inevitable. Because patient education is such a vital aspect of the prevention and treatment of overweight and obesity and related conditions, it is each practitioners' responsibility to ensure that information and instructions are explained in such a way that allows for patient understanding. When there is an obvious disconnect in the communication process between the practitioner and patient due to the patient's lack of proficiency in the English language, an interpreter is required.
In this multicultural landscape, interpreters are a valuable resource to help bridge the communication and cultural gap between clients/patients and practitioners. Interpreters are more than passive agents who translate and transmit information back and forth from party to party. When they are enlisted and treated as part of the interdisciplinary clinical team, they serve as cultural brokers, who ultimately enhance the clinical encounter.
There is limited insurance coverage for obesity treatments.
In 2004, Medicare, the federal program for health services for the elderly and disabled, made revisions to its Medicare Coverage Issues Manual, which removed language stating that obesity was not a disease or illness. Previously, the Medicare program did recognize gastric bypass surgery in some cases for an underlying condition that caused obesity. However, because Medicare was required to cover only "medically necessary services for illness or injury," the previous wording prevented most obesity treatments from being covered . While this revision did not change coverage directly, it allows individuals or organizations to request that specific treatments be evaluated to determine if potential beneficial effects are supported by current medical evidence. Additionally, medical nutrition therapy is a supported treatment. For more information regarding Medicare services, please visit http://www.cms.gov/home/medicare.asp.
Starting in January 2006, Medicare began to offer prescription drug plans, whereby it would assist in the payment of enrolled individuals' medications. Weight-loss medications such as orlistat may be covered; many variables contribute to the amount of coverage available. Effective in 2006, Medicare/Medicaid covers RYGB, BPD/DS (or gastric reduction duodenal switch), and LGB for patients with BMIs of 35 or greater, who have one or more comorbid conditions, and who have unsuccessfully attempted behavioral or pharmacologic interventions . All other bariatric surgeries for obesity alone are not covered. As of 2013, the procedures are not required to be performed at an approved facility . Medicare/Medicaid provides more information and implementation tools on its website at http://www.cms.gov.
Additionally, in 2011 Medicare/Medicaid began to cover preventive services to reduce obesity, including screening and counseling for eligible beneficiaries . Persons with a BMI of 30 or greater qualify for one month of once-weekly counseling sessions, one session every other week for months 2 through 6, and if the patient loses 3 kg in the first 6 months, one session per month during months 7 through 12.
Medicaid is a jointly funded, federal-state health insurance program for certain low-income and needy people. Some Medicaid programs do pay for obesity surgery, although the number of such claims appears small. This may be due to either low interest in the procedure or possibly due to low reimbursement rates, and thus limited surgeons who are willing to perform the procedure for Medicaid patients. The federal statute governing Medicaid coverage of pharmacological compounds specifically excludes payment for drugs for weight loss. However, states can apply for a waiver from this provision. Many states have received such a waiver and do cover orlistat. For the most accurate information regarding your specific state's coverage policies, contact the state Medicaid office.
The 2010 Affordable Care Act (ACA) represents a significant shift in the delivery of private healthcare insurance and is estimated to impact 56 million privately insured Americans who are obese as of 2014 . Medicare will cover approximately 5 million obese individuals, and another 4 million are expected to be covered through state exchanges. Before January 2014, 35 states allowed insurers to charge more for coverage and two states explicitly permitted denial of coverage solely based on obesity status . In the past, approximately 9% of existing policy cancellations were based on BMI. Annual and lifetime caps on reimbursements for obesity treatments are also nullified by the ACA.
Private insurers are now required to reimburse for screenings and counseling sessions for obese patients based on level A or B recommendations of the U.S. Preventive Services Task Force (e.g., intensive behavioral therapy for obesity, usually 12 to 26 sessions per year). In this respect, private insurers are now required to offer the same services as Medicare and various state Medicaid programs. Additionally, the ACA promotes employer wellness programs, which offer incentives (i.e., decreased healthcare premiums) for individuals who demonstrate a reduction in weight or BMI (among other healthy changes, including tobacco use reduction/cessation and achievement of cholesterol targets) . Grandfathered plans are also required to provide preventive services for obesity. Discrimination based on weight is no longer allowed, which is a step toward expanding preventive care. However, the ACA included rules that allowed individual states to decide which types of treatment options would be available to obese patients in individual, family, and small-group plans (as well as state plans). As of 2015, 28 states do require private insurers to cover bariatric surgery or enrollment in weight-loss programs . Coverage of weight-loss drugs is also not required by the ACA, but individual providers may pay for these medications.
In 2002, the IRS announced a new policy (IRS Ruling 2002-19) stating that, "Obesity is medically accepted to be a disease in its own right." For taxpayers, this means that treatment specifically for obesity can be claimed as a medical deduction under certain conditions. According to the IRS :
"Uncompensated amounts paid by individuals for participation in a weight-loss program as treatment for a specific disease or diseases (including obesity) diagnosed by a physician are expenses for medical care that are deductible under § 213, subject to the limitations of that section."
This policy will likely help individuals who have high expenses related to their obesity, who itemize their deductions, and who are eligible for the medical deduction. In addition, the ruling applies to individuals who can participate in a flexible savings account because those programs use the same IRS rules. This means that many persons can put aside pre-tax dollars to use for weight management during the year.
The text of the ruling is available at http://www.irs.gov/pub/irs-irbs/irb02-16.pdf. Patients should contact a tax professional when considering this deduction.
The number of overweight and obese people has reached epidemic proportions. Estimates show that 75% of the adult population is either overweight or obese. This represents a substantial increase from just 20 years ago. Ample scientific evidence exists that demonstrates an increasing body mass index corresponds to increasing morbidity and mortality. Numerous treatments for obesity are available. The cornerstone of any treatment regimen is behavioral modification, focusing on diet changes and exercise regimens. Additional therapies include drugs and surgery. To improve care for overweight and obese patients, physicians and other providers need to have a thorough understanding of obesity and its treatment and to understand the importance of addressing the topic with patients. In addition, they must recognize that recidivism and failure are quite high and that successful treatment requires a concerted and sustained effort.
|CDC Resources and Publications for Overweight and Obesity|
|Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults|
|Dietary Guidelines for Americans|
|Exercise and Physical Activity: Your Everyday Guide from the National Institute on Aging|
|AHA Diet and Lifestyle Recommendations|
|Institute of Medicine (IOM) Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids (Macronutrients)|
|Guide to Clinical Preventive Services|
|NHLBI Obesity Education Initiative|
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