Treatment of Obesity

Abstract

For primary care physicians, obesity is one of the most challenging problems confronted in office practice. The disorder is increasing in prevalence despite the efforts of both patients and physicians. Treatment requires a multimodality approach that addresses diet, physical activity, and behavioral issues. Medication and surgical approaches may be appropriate as well. This review outlines the evidence for each approach, suggests how primary care physicians can best help obese patients, and provides practical tips for weight loss. For primary care physicians, obesity is one of the most challenging problems confronted in office practice. The disorder is increasing in prevalence despite the efforts of both patients and physicians. Treatment requires a multimodality approach that addresses diet, physical activity, and behavioral issues. Medication and surgical approaches may be appropriate as well. This review outlines the evidence for each approach, suggests how primary care physicians can best help obese patients, and provides practical tips for weight loss. Obesity is a rapidly growing epidemic worldwide, and it increases the risk of morbidity and mortality. In the United States, obesity may be responsible for as many as 300,000 deaths per year,1Allison DB Fontaine KR Manson JE Stevens J VanItallie TB Annual deaths attributable to obesity in the United States.JAMA. 1999; 282: 1530-1538Crossref PubMed Scopus (1517) Google Scholar although this figure is controversial.2Flegal KM Graubard BI Williamson DF Gail MH Excess deaths associated with underweight, overweight, and obesity.JAMA. 2005; 293: 1861-1867Crossref PubMed Scopus (2143) Google Scholar Direct medical costs in the United States (1999) are estimated to be $70 billion annually.3Colditz GA Economic costs of obesity and inactivity.Med Sci Sports Exerc. 1999; 31: S663-S667PubMed Google Scholar Despite the expenditure of billions of dollars in weight-loss products, the epidemic is getting worse. The most common definition of obesity is a body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) of 30 kg/m2 or greater. Overweight is defined as a BMI between 25.0 and 29.9 kg/m2, and extreme obesity is defined as a BMI of 40 kg/m2 or greater. Approximately one third of Americans are overweight, one third are obese, and 4.5% have extreme obesity.4Ogden CL Carroll MD Curtin LR McDowell MA Tabak CJ Flegal KM Prevalence of overweight and obesity in the United States, 1999-2004.JAMA. 2006; 295: 1549-1555Crossref PubMed Scopus (7390) Google Scholar Unfortunately, physicians often do not formally diagnose obesity when it exists (Bardia A, Holtan SG, Slezak JM, Thompson WG, unpublished data, 2006).5Stafford RS Radley DC National trends in antiobesity medication use.Arch Intern Med. 2003; 163: 1046-1050Crossref PubMed Scopus (96) Google Scholar, 6Ruser CB Sanders L Brescia GR et al.Identification and management of overweight and obesity by internal medicine residents.J Gen Intern Med. 2005; 20: 1139-1141Crossref PubMed Scopus (52) Google Scholar Assessment of patients for obesity can be facilitated by having office staff enter the BMI into the patient's record after measuring height and weight. Measuring waist and hip circumference should also be considered because these parameters affect outcome independent of the BMI.7Yusuf S Hawken S Ounpuu S INTERHEART Study Investigators et al.Obesity and the risk of myocardial infarction in 27,000 participants from 52 countries: a case-control study.Lancet. 2005; 366: 1640-1649Abstract Full Text Full Text PDF PubMed Scopus (2203) Google Scholar Physician diagnosis of obesity is important because a management plan is more likely to be formulated than when no diagnosis is made.6Ruser CB Sanders L Brescia GR et al.Identification and management of overweight and obesity by internal medicine residents.J Gen Intern Med. 2005; 20: 1139-1141Crossref PubMed Scopus (52) Google Scholar, 8McArtor RE Iverson DC Benken D Dennis LK Family practice residents' identification and management of obesity.Int J Obes Relat Metab Disord. 1992; 16: 335-340PubMed Google Scholar This review focuses on optimizing that management plan. Weight loss requires a sustained negative energy balance: energy output must exceed energy intake. We recommend a 2092-kJ (500-kcal) daily deficit, which can be expected to lead to a weight loss of 0.45 kg per week.9Wadden TA Foster GD Behavioral treatment of obesity.Med Clin North Am. 2000; 84: 441-461Abstract Full Text Full Text PDF PubMed Scopus (245) Google Scholar Although it is theoretically possible to achieve this amount of weight loss through either reduced energy intake or increased energy output, a 2092-kJ daily deficit is best achieved and sustained by a combination of the two. This review focuses first on strategies for reducing energy intake (diets, drugs, and bariatric surgery), then discusses strategies for increasing energy output (exercise and nonexercise movement), and concludes with guidelines for how primary care physicians can help their obese patients successfully change their energy intake and physical activity level. Many different diets have been advocated for weight loss, but there is little scientific evidence to recommend one diet over another. Dansinger et al10Dansinger ML Gleason JA Griffith JL Selker HP Schaefer EJ Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial.JAMA. 2005; 293: 43-53Crossref PubMed Scopus (1303) Google Scholar compared 4 approaches, the Atkins (low carbohydrate), Zone (high protein, low carbohydrate), Ornish (very low fat), and Weight Watchers diets, and found no significant difference in weight loss at 1 year. Other studies have shown greater weight loss at 3 months with low-carbohydrate than with other diets but no significant difference at 1 year.11Foster GD Wyatt HR Hill JO et al.A randomized trial of a low-carbohydrate diet for obesity.N Engl J Med. 2003; 348: 2082-2090Crossref PubMed Scopus (1406) Google Scholar, 12Stern L Iqbal N Seshadri P et al.The effects of low-carbohydrate versus conventional weight loss diets in severely obese adults: one-year follow-up of a randomized trial.Ann Intern Med. 2004; 140: 778-785Crossref PubMed Scopus (705) Google Scholar While some small studies of low-glycemic index diets have shown a benefit,13Slabber M Barnard HC Kuyl JM Dannhauser A Schall R Effects of a low-insulin-response, energy-restricted diet on weight loss and plasma insulin concentrations in hyperinsulinemic obese females.Am J Clin Nutr. 1994; 60: 48-53PubMed Google Scholar, 14Ebbeling CB Leidig MM Sinclair KB Hangen JP Ludwig DS A reduced-glycemic load diet in the treatment of adolescent obesity.Arch Pediatr Adolesc Med. 2003; 157: 773-779Crossref PubMed Scopus (361) Google Scholar others have found little effect beyond that of energy restriction.15Thompson WG Rostad Holdman N Janzow DJ Slezak JM Morris KL Zemel MB Effect of energy-reduced diets high in dairy products and fiber on weight loss in obese adults.Obes Res. 2005; 13: 1344-1353Crossref PubMed Scopus (164) Google Scholar, 16Raatz SK Torkelson CJ Redmon JB et al.Reduced glycemic index and glycemic load diets do not increase the effects of energy restriction on weight loss and insulin sensitivity in obese men and women.J Nutr. 2005; 135: 2387-2891PubMed Scopus (87) Google Scholar A high-protein diet may facilitate weight loss,17Due A Toubro S Skov AR Astrup A Effect of normal-fat diets, either medium or high in protein, on body weight in overweight subjects: a randomised 1-year trial.Int J Obes Relat Metab Disord. 2004; 28: 1283-1290Crossref PubMed Scopus (237) Google Scholar but more and larger studies are needed to confirm this hypothesis. Calcium and dairy products have also been postulated to facilitate weight loss, but to date most randomized trials have not confirmed this theory.15Thompson WG Rostad Holdman N Janzow DJ Slezak JM Morris KL Zemel MB Effect of energy-reduced diets high in dairy products and fiber on weight loss in obese adults.Obes Res. 2005; 13: 1344-1353Crossref PubMed Scopus (164) Google Scholar One strategy for reducing energy intake is to reduce fat content. The Women's Health Initiative Randomized Controlled Dietary Modification Trial randomized 19,541 women to a low-fat diet with increased amounts of fruits, vegetables, and whole grains and 29,294 women to a control diet.18Howard BV Manson JE Stefanick ML et al.Low-fat dietary pattern and weight change over 7 years: the Women's Health Initiative Dietary Modification Trial.JAMA. 2006; 295: 39-49Crossref PubMed Scopus (344) Google Scholar The study found a significant correlation between dietary fat reduction with increased fruit and vegetable consumption and weight loss. Further evidence for a reduced-fat approach comes from the National Weight Control Registry, a self-report registry of subjects who have lost at least 13.6 kg and maintained that loss for 1 to 5 years.19Klem ML Wing RR McGuire MT Seagle HM Hill JO A descriptive study of individuals successful at long-term maintenance of substantial weight loss.Am J Clin Nutr. 1997; 66: 239-246PubMed Google Scholar These subjects reported that only 25% of their total energy intake came from fat, which is considerably lower than the national average of 37%. However, fat restriction without energy reduction will not result in weight loss.20Schlundt DG Hill JO Pope-Cordle J Arnold D Virts KL Katahn M Randomized evaluation of a low fat ad libitum carbohydrate diet for weight reduction.Int J Obes Relat Metab Disord. 1993; 17: 623-629PubMed Google Scholar Reducing fat in the diet reduces the energy density of the diet. Energy density is the ratio of energy provided (calories) by a food to its weight. Foods with low energy density such as fruits and vegetables provide considerable bulk with minimal energy intake (filling but not fattening). Thus, a pound (0.45 kg) of carrots, which have low energy density, has the same amount of energy value (calories) as an ounce (28 g) of peanuts, which have high energy density. A crossover study21Rolls BJ Roe LS Meengs JS Reductions in portion size and energy density of foods are additive and lead to sustained decreases in energy intake.Am J Clin Nutr. 2006; 83: 11-17PubMed Google Scholar compared the effect of reducing portion size with the effect of reducing energy density on energy intake. When portion size was reduced by 25%, energy intake declined by 10%, but when energy density was reduced by 25%, energy intake declined by more than 20%. The group randomized to a diet of foods with reduced energy density consumed more food but less energy than the group whose diet consisted of reduced portion size. The subjects' ratings of hunger and taste did not vary across the comparisons. Although more investigation is needed, there is some evidence that increasing the amount of low-energy density foods in the diet is effective for long-term weight management as well.22Rolls BJ Roe LS Beach AM Kris-Etherton PM Provision of foods differing in energy density affects long-term weight loss.Obes Res. 2005; 13: 1052-1060Crossref PubMed Scopus (128) Google Scholar In summary, long-term weight loss and weight maintenance require a reduction in energy intake. We believe this is best achieved by a combination of reducing total fat intake, reducing portion size, reducing energy density, and increasing fruit and vegetable intake. However, in the absence of behavior modification and continued input from health professionals, diets are ineffective in the long term.23Wadden TA Berkowitz RI Womble LG et al.Randomized trial of lifestyle modification and pharmacotherapy for obesity.N Engl J Med. 2005; 353: 2111-2120Crossref PubMed Scopus (634) Google Scholar Counseling patients regarding behavior modification that will successfully reduce fat and energy intake is addressed subsequently in this article (see Facilitating Behavior Change section). The role of medications in weight loss is controversial, and their effectiveness appears to be limited. First, the amount of weight lost with use of drugs is small (as discussed subsequently). Second, the long-term safety of weight-loss drugs is not established, and the occurrence of adverse effects (such as the cardiac valve abnormalities associated with fenfluramine) suggests that this is an important consideration. Finally, when weight-loss drugs are discontinued, weight is regained. Because no weight-loss drug has been approved by the Food and Drug Administration (FDA) for use for more than 2 years, drugs represent a short-term solution to a long-term problem with only modest benefit and with unclear risk. The decision to prescribe medication hinges on whether the patient will become more or less motivated to make the long-term changes in eating and activity that are necessary to lose weight and keep it off. Until safety data are available, physicians should refrain from prescribing medications for weight loss for durations longer than those approved by the FDA. Phentermine, benzphetamine, and phendimetrazine are FDA approved for short-term use (12 weeks) for weight loss. Meta-analysis suggests a short-term weight loss of 3.5 kg with phentermine,24Haddock CK Poston WS Dill PL Foreyt JP Ericsson M Pharmacotherapy for obesity: a quantitative analysis of four decades of randomized clinical trials.Int J Obes Relat Metab Disord. 2002; 26: 262-273Crossref PubMed Scopus (232) Google Scholar but no long-term data are available. Until long-term studies demonstrate the effectiveness and safety of these drugs, they are best avoided. Sibutramine is a norepinephrine and serotonin reuptake inhibitor that is thought to lead to reduced food intake. 25DeWald T Khaodhiar L Donahue MP Blackburn G Pharmacological and surgical treatments for obesity.Am Heart J. 2006; 151: 604-624Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar In a meta-analysis of 29 trials, sibutramine use resulted in a weight loss of 4.5 kg at 1 year.26Arterburn DE Crane PK Veenstra DL The efficacy and safety of sibutramine for weight loss: a systematic review.Arch Intern Med. 2004; 164: 994-1003Crossref PubMed Scopus (235) Google Scholar A more recent study found that sibutramine use alone resulted in a weight loss of 5 kg at 1 year compared with 6.7 kg with lifestyle modification alone and 12.1 kg with sibutramine plus lifestyle modification.23Wadden TA Berkowitz RI Womble LG et al.Randomized trial of lifestyle modification and pharmacotherapy for obesity.N Engl J Med. 2005; 353: 2111-2120Crossref PubMed Scopus (634) Google Scholar Blood pressure and heart rate increase modestly with sibutramine use and should be monitored. Palpitations may also occur. Sibutramine should not be used by patients with cardiovascular disease, heart failure, or arrhythmias or by patients taking selective serotonin reuptake inhibitors or monoamine oxidase inhibitors.25DeWald T Khaodhiar L Donahue MP Blackburn G Pharmacological and surgical treatments for obesity.Am Heart J. 2006; 151: 604-624Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar No studies lasting longer than 2 years have been reported, and sibutramine is approved by the FDA for 1-year use. Topiramate and rimonabant are associated with weight loss but are not yet approved by the FDA for this purpose. Topiramate, which modulates γ-aminobutyric acid receptors, was associated with a 6% weight loss in a meta-analysis (24-week data with several studies reported in abstract form) but was also associated with a significant incidence of adverse central nervous system effects (especially paresthesias and loss of taste).27Li Z Maglione M Tu W et al.Meta-analysis: pharmacologic treatment of obesity.Ann Intern Med. 2005; 142: 532-546Crossref PubMed Scopus (640) Google Scholar Rimonabant is a cannabinoid-1 receptor blocker not yet approved for use in the United States. Two large randomized trials have demonstrated efficacy, reporting a 6-kg weight loss at 1 year.28Van Gaal LF Rissanen AM Scheen AJ Ziegler O Rossner S RIO-Europe Study Group Effects of the cannabinoid-1 receptor blocker rimonabant on weight reduction and cardiovascular risk factors in overweight patients: 1-year experience from the RIO-Europe study [published correction appears in Lancet. 2005;366:370].Lancet. 2005; 365: 1389-1397Abstract Full Text Full Text PDF PubMed Scopus (1412) Google Scholar, 29Pi-Sunyer FX Aronne LJ Heshmati HM Devin J Rosenstock J RIO-North America Study Group Effect of rimonabant, a cannabinoid-1 receptor blocker, on weight and cardiometabolic risk factors in overweight or obese patients: RIO-North America: a randomized controlled trial [published correction appears in JAMA. 2006;295:1252].JAMA. 2006; 295: 761-775Crossref PubMed Scopus (1114) Google Scholar Because both studies had a considerable number of dropouts, the reported weight loss may be optimistic.30Simons-Morton DG Obarzanek E Cutler JA Obesity research—limitations of methods, measurements, and medications [editorial].JAMA. 2006; 295: 826-828Crossref PubMed Scopus (56) Google Scholar The incidence of psychiatric problems (depression and anxiety) in the patients taking rimonabant was significantly higher (approximately double) than that seen in the placebo groups, a finding that warrants further investigation. Orlistat prevents absorption of a portion of the energy fraction from ingested fats. Many randomized trials of orlistat have been conducted, and most have shown greater weight loss with orlistat than with placebo. However, meta-analysis suggests that the mean weight loss is only 2.89 kg.27Li Z Maglione M Tu W et al.Meta-analysis: pharmacologic treatment of obesity.Ann Intern Med. 2005; 142: 532-546Crossref PubMed Scopus (640) Google Scholar When patients are switched from a weight-loss to a weight-maintenance diet, they regain less weight if they continue orlistat than if they switch to placebo.31Davidson MH Hauptman J DiGirolamo M et al.Weight control and risk factor reduction in obese subjects treated for 2 years with orlistat: a randomized controlled trial [published correction appears in JAMA 1999;281: 1174].JAMA. 1999; 281: 235-242Crossref PubMed Scopus (827) Google Scholar The studies in the meta-analysis showed a reduction in low-density lipoprotein cholesterol, glucose, insulin, and hemoglobin A1c (in diabetics) with orlistat, which occurred both as a result of weight loss and independent of weight loss (probably because the orlistat group absorbed less fat). Orlistat improves glucose tolerance and reduces the rate of progression to impaired glucose tolerance and diabetes.32Torgerson JS Hauptman J Boldrin MN Sjöström L XENical in the prevention of diabetes in obese subjects (XENDOS) study: a randomized study of orlistat as an adjunct to lifestyle changes for the prevention of type 2 diabetes in obese patients [published correction appears in Diabetes Care. 2004;27: 856].Diabetes Care. 2004; 27: 155-161Crossref PubMed Scopus (1486) Google Scholar Orlistat improves alanine transaminase levels and steatosis in patients with nonalcoholic fatty liver disease independent of weight loss.33Zelber-Sagi S Kessler A Brazowsky E et al.A double-blind randomized placebo-controlled trial of orlistat for the treatment of nonalcoholic fatty liver disease.Clin Gastroenterol Hepatol. 2006 May; 4 (Epub 2006 Apr 17.): 639-644Abstract Full Text Full Text PDF PubMed Scopus (256) Google Scholar Gastrointestinal adverse effects such as diarrhea and oily stool are common (especially if the diet is high in fat) but usually subside with time, and serious adverse events appear to be rare. Orlistat costs more than $100 a month and may not be covered by insurance. It is best suited for patients who can comply with a low-fat diet, are at high risk of developing diabetes, and can afford the medication. The longest published study of orlistat use is 4 years,32Torgerson JS Hauptman J Boldrin MN Sjöström L XENical in the prevention of diabetes in obese subjects (XENDOS) study: a randomized study of orlistat as an adjunct to lifestyle changes for the prevention of type 2 diabetes in obese patients [published correction appears in Diabetes Care. 2004;27: 856].Diabetes Care. 2004; 27: 155-161Crossref PubMed Scopus (1486) Google Scholar and the drug is FDA approved for 2-year use. Approval for over-the-counter formulations (half dose) is expected soon. Combined treatment with multiple weight-loss drugs has received little evaluation to date and cannot be recommended at this time. One study that combined orlistat and sibutramine showed no greater weight loss with the combination regimen than with sibutramine alone.34Wadden TA Berkowitz RI Womble LG Sarwer DB Arnold ME Steinberg CM Effects of sibutramine plus orlistat in obese women following 1 year of treatment by sibutramine alone: a placebo-controlled trial.Obes Res. 2000; 8: 431-437Crossref PubMed Scopus (109) Google Scholar Bariatric surgery rates have increased substantially,35Santry HP Gillen DL Lauderdale DS Trends in bariatric surgical procedures.JAMA. 2005; 294: 1909-1917Crossref PubMed Scopus (774) Google Scholar but this procedure may still be underused.36Wolfe BM Morton JM Weighing in on bariatric surgery: procedure use, readmission rates, and mortality [editorial].JAMA. 2005; 294: 1960-1963Crossref PubMed Scopus (75) Google Scholar Although no long-term randomized trials have been conducted, bariatric surgery is the only treatment that has been reported to result in substantial 10-year weight loss.37Sjöström L Lindroos AK Peltonen M Swedish Obese Subjects Study Scientific Group et al.Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery.N Engl J Med. 2004; 351: 2683-2693Crossref PubMed Scopus (3273) Google Scholar, 38Pories WJ MacDonald Jr, KG Morgan EJ et al.Surgical treatment of obesity and its effect on diabetes: 10-y follow-up.Am J Clin Nutr. 1992; 55: 582S-585SPubMed Google Scholar Bariatric surgery results in long-term reduction in energy intake and is associated with increased physical activity.37Sjöström L Lindroos AK Peltonen M Swedish Obese Subjects Study Scientific Group et al.Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery.N Engl J Med. 2004; 351: 2683-2693Crossref PubMed Scopus (3273) Google Scholar Furthermore, morbidity from obesity can be altered substantially by bariatric surgery. In a recent systematic review and meta-analysis, Buchwald et al39Buchwald H Avidor Y Braunwald E et al.Bariatric surgery: a systematic review and meta-analysis [published correction appears in JAMA. 2005;293:1728].JAMA. 2004; 292: 1724-1737Crossref PubMed Scopus (5385) Google Scholar reported that diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea resolved or improved in more than half of the patients who had these conditions preoperatively. Surgery has not been proved to reduce mortality; long-term randomized trials are not yet available to answer this question. Mortality rates associated with bariatric surgery are low and vary by type of procedure and surgical experience.Mortality is estimated to be 0.1% for gastric banding, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch procedures.39Buchwald H Avidor Y Braunwald E et al.Bariatric surgery: a systematic review and meta-analysis [published correction appears in JAMA. 2005;293:1728].JAMA. 2004; 292: 1724-1737Crossref PubMed Scopus (5385) Google Scholar Excess weight loss (excess weight = total body weight - ideal body weight) is 47.5% with gastric banding, 61.6% with gastric bypass, and 70.1% with biliopancreatic diversion or duodenal switch procedures.39Buchwald H Avidor Y Braunwald E et al.Bariatric surgery: a systematic review and meta-analysis [published correction appears in JAMA. 2005;293:1728].JAMA. 2004; 292: 1724-1737Crossref PubMed Scopus (5385) Google Scholar The surgical team and the patient should balance the risks and benefits of these various techniques when selecting the appropriate operation. Both greater surgeon and center experience are associated with reduced mortality and fewer complications.36Wolfe BM Morton JM Weighing in on bariatric surgery: procedure use, readmission rates, and mortality [editorial].JAMA. 2005; 294: 1960-1963Crossref PubMed Scopus (75) Google Scholar Complications after bariatric surgery are common, and as many as 20% of patients are rehospitalized during the first postoperative year.40Zingmond DS McGory ML Ko CY Hospitalization before and after gastric bypass surgery.JAMA. 2005; 294: 1918-1924Crossref PubMed Scopus (179) Google Scholar Short-term complications include wound infection, anastomosis ulceration, stomal stenosis, and constipation, while long-term adverse effects include excessively severe dumping syndrome, nutritional deficiencies, and cholecystitis.41Abell TL Minocha A Gastrointestinal complications of bariatric surgery: diagnosis and therapy.Am J Med Sci. 2006; 331: 214-218Crossref PubMed Scopus (93) Google Scholar, 42Malinowski SS Nutritional and metabolic complications of bariatric surgery.Am J Med Sci. 2006; 331: 219-225Crossref PubMed Scopus (218) Google Scholar When feasible, laparoscopic gastric bypass appears to be more cost-effective than open gastric bypass.43Paxton JH Matthews JB The cost effectiveness of laparoscopic versus open gastric bypass surgery.Obes Surg. 2005; 15: 24-34Crossref PubMed Scopus (55) Google Scholar Although the initial procedure and treatment of subsequent complications are expensive, medication costs decrease considerably after bariatric surgery,44Snow LL Weinstein LS Hannon JK et al.The effect of Roux-en-Y gastric bypass on prescription drug costs.Obes Surg. 2004; 14: 1031-1035Crossref PubMed Scopus (37) Google Scholar and several investigators have concluded that it is a cost-effective procedure.45Clegg A Colquitt J Sidhu M Royle P Walker A Clinical and cost effectiveness of surgery for morbid obesity: a systematic review and economic evaluation.Int J Obes Relat Metab Disord. 2003; 27: 1167-1177Crossref PubMed Scopus (133) Google Scholar, 46Craig BM Tseng DS Cost-effectiveness of gastric bypass for severe obesity.Am J Med. 2002; 113: 491-498Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar Table 1 lists criteria for bariatric surgery. Patients with extreme obesity (BMI, ≥40 kg/m2) and recently diagnosed complications of obesity such as diabetes, metabolic syndrome, and obstructive sleep apnea are particularly good surgical candidates. We recommend a thorough preoperative evaluation by a multispecialty team including nutritionists, psychologists, and surgeons. A detailed preoperative psychological evaluation is necessary because depression is an important potential barrier to sustaining weight loss.47Clark MM Balsiger BM Sletten CD et al.Psychosocial factors and 2-year outcome following bariatric surgery for weight loss.Obes Surg. 2003; 13: 739-745Crossref PubMed Scopus (107) Google Scholar Binge-eating disorder should be identified and treated. With good psychosocial support, surgery has been successful in patients with binge-eating disorder.48Busetto L Segato G DeLuca M et al.Weight loss and postoperative complications in morbidly obese patients with binge eating disorder treated by laparoscopic adjustable gastric banding.Obes Surg. 2005; 15: 195-201Crossref PubMed Scopus (93) Google Scholar, 49Buddeberg-Fischer B Klaghofer R Krug L et al.Physical and psychosocial outcome in morbidly obese patients with and without bariatric surgery: a 4 ½-year follow-up.Obes Surg. 2006; 16: 321-330Crossref PubMed Scopus (65) Google Scholar Patients should be educated regarding (1) what to expect from surgery (it typically produces a transition from extreme obesity to mild obesity but rarely results in losses sufficient to attain normal weight), (2) the potential complications of bariatric surgery, (3) postoperative medical therapy (many patients are treated with ursodiol to prevent gallstones, iron supplements, and vitamins to prevent nutritional deficiencies), and (4) the cost of the procedure ($35,000), which is not always covered by insurance. The preoperative evaluation and education process can be expected to take at least 3 to 6 months.TABLE 1Criteria for Bariatric SurgeryAdapted from the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. Gastrointestinal Surgery for Severe Obesity. Bethesda, Md: National Institutes of Health; December 2004. NIH Publication No. 04-4006. Body mass index of 40 kg/m2 or more (approximately 45 kg overweight for men and 36 kg for women) orBody mass index between 35 and 39.9 kg/m2 and a serious obesity-related health problem such as type 2 diabetes, heart disease, or severe sleep apneaThe patient should Understand the operation and the lifestyle changes that will be neededBe unlikely to lose weight or maintain weight loss long term with nonsurgical measuresBe well informed about the surgical procedure and the effects of treatmentBe motivated to lose weight and improve healthBe aware of how life may change after the operation (eg, the need to chew food well and the inability to eat large meals)Have no psychological contraindications to obesity surgery such as untreated depression or personality disordersBe aware of the potential for serious complications, dietary restrictions, and occasional failuresBe committed to lifelong medical follow-up and vitamin/mineral supplementationRealize that no method, including surgery, is guaranteed to produce and maintain weight loss and that success is possible only with long-term commitment to behavioral change and medical follow-up Open table in a new tab Most studies have demonstrated no or modest weight loss with exercise alone (2 kg) or with exercise added to diet (3 kg).50Bens