Behavioral Weight Control
A comprehensive behavioral weight control program, comprising components of improved eating habits, lifestyle change, and increased exercise, is widely viewed as the treatment of choice for overweight and moderately obese individuals. With 5 months of treatment, behavioral treatment combined with moderate dietary restriction (e.g., 1000–1500 kcal/day of self-selected foods) results in a mean weight loss of 15–20 pounds
(96). Behavioral weight loss programs are also associated with significant decreases in depression and body image dissatisfaction, together with increases in self-esteem and interpersonal functioning
(97). The problem is that these treatment effects are not maintained over time.
At 1-year follow-up, patients who have received behavioral treatment with dietary restriction regain 35%–50% of their weight loss, both in research clinics and in the general population. Five-year follow-ups have revealed that the vast majority of patients regained all of the weight they had lost. A large and diverse literature is strikingly consistent in showing the same inexorable pattern, namely, gradual regain of weight over time
(98). Viewing obesity as a chronic condition, it is not surprising that improvement recedes once treatment has stopped. Accordingly, a continuous care model has been proposed
(2). Extended maintenance sessions have improved persistence of weight loss, but attendance declines after 6 months
(99).
Behavioral treatment combined with a very low calorie diet of up to 800 kcal/day, often in the form of a liquid nutritional supplement, was highly touted and widely used several years ago. Typical programs used a very low calorie diet for 12–16 weeks, followed by reintroduction of a self-selected 1000–1500 kcal/day diet. This approach produces more rapid weight loss initially, but relapse occurs more quickly, so that treated individuals, after 1 year, show similar weight regain to those on more moderate calorie restriction
(100).
A notable contrast to the high relapse rate among obese adults is the outcome in children. Weight loss has been maintained over a 10-year follow-up in children, even though their parents showed the predictable relapse rate
(101). It may be easier to teach children healthy eating and activity habits. Moreover, the parents in these studies provided a structured environment that supported weight control by regulating access to food
(102). This structure had the effect of lessening reliance on self-control that may be insufficient in the long term to cope with the pressures of a toxic environment
(28).
Predictors of weight loss have proven elusive. Personality traits, measures of psychopathology, presence of binge eating, dietary restraint, and history of weight cycling have all proven unreliable
(103). The process variables of early weight loss and compliance with self-monitoring are the most useful predictors
(103,
104). Patients who do neither present very poor risk for treatment. Adherence to an exercise regimen is a reliable correlate of maintenance of weight loss
(105,
106).
Pharmacotherapy
Adding weight loss medications to the behavioral treatment of obesity results in weight loss 5–20 lbs. greater than that seen with behavioral treatment alone
(107). The majority of weight loss occurs over the initial 6 months, with most studies showing relative stability of weight over the ensuing 6 months of medication treatment. There is little information on the safety or efficacy of drug treatment for more than 1 year, but studies of longer treatment indicate that gradual regain occurs in many patients
(108,
109). Weight loss medications are similar to medications used to treat other chronic medical conditions; that is, they don’t work when they are not taken. The vast majority of studies have found that weight is quickly regained when medication is discontinued
(107). Therefore, it makes little sense to use obesity medications short term, in the hope that they will provide a “jump start” for patient motivation.
After the 1992 publication of the Weintraub study
(110), showing the efficacy of long-term use of fenfluramine/phentermine therapy, an exponential increase in the use of these agents occurred
(111). The subsequent finding that the serotonergic reuptake and releasing agents fenfluramine and dexfenfluramine were associated with valvular insufficiency led to their withdrawal from the market
(112). The lesson learned is that treatments have potential risks. Where the risk-to-benefit ratio of longer-term treatment is largely unknown, as is the case with many weight loss drugs, the prescribing physician should have a high threshold for instituting treatment.
For obesity, current recommendations include prescription of weight loss medications only for patients with a body mass index >30 kg/m
2 without or >27 kg/m
2 with associated comorbid conditions such as type 2 diabetes
(2). Two medications are currently approved for long-term use. Sibutramine is a selective serotonin and norepinephrine reuptake inhibitor whose efficacy is similar to that of other single-drug treatments
(113). In short-term studies, it has not been associated with valvular heart disease
(114). The primary limiting factors for its use are elevations in pulse and blood pressure, which are usually modest, but can be significant in some patients
(115). Another new weight-loss medication, orlistat, is a gastrointestinal lipase inhibitor, which leads to approximately one-third of ingested dietary fat being excreted in the stool
(116). Its efficacy for weight loss and weight maintenance is similar to that of other obesity drugs, and it appears to have favorable impact on obesity-related comorbidity
(109). Side effects are gastrointestinal, such as loose stools and oily spotting, and are related to the amount of dietary fat ingested, which may aid in adherence to a low-fat diet. Fat-soluble vitamin absorption is also decreased, and multivitamin supplementation is recommended. Other medications, including leptin, are in earlier stages of development, and are likely to be years away from approval.
Older medications used to treat obesity, including phentermine (half of the “fen/phen” combination), phendimetrazine, mazindol, and other adrenergic agents are not approved for long-term use. The use of SSRIs as weight control agents has shown disappointing results. Regarding combination therapy, there have been few controlled studies demonstrating the safety or efficacy of any drug combination for the treatment of obesity, including fluoxetine/phentermine, orlistat/phentermine, or others. The combined use of medications, except in the context of clinical studies with full informed consent, should be discouraged
(107).
The NIH Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults provides guidance on acceptable use of weight loss medications in the treatment of obesity. The guidelines may be downloaded from http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm.
Surgery
Gastrointestinal surgery appears to be the most effective treatment for some severely obese individuals with class III obesity (body mass index of 40 kg/m
2 or more) or class II obesity (body mass index of 35–39.9 kg/m
2) with comorbid medical conditions such as sleep apnea or type 2 diabetes. The most commonly used procedures are gastric bypass (e.g., Roux-en-Y gastrojejunostomy) and gastric restriction (e.g., vertical banded gastroplasty). On average, patients maintain a weight loss of 25%–40% of their preoperative body weight after these procedures
(117). Lipectomy and liposuction are cosmetic procedures that do not yield medically significant weight loss
(118).
It is important for prospective patients to realize a number of things. As with any major surgery, there are operative mortality risks estimated at 0.3%–1.6% in specialized centers, short-term complications such as peritonitis and anastomotic leaks in 1.6%–2.3% of patients, and long-term complications such as cholelithiasis and vitamin and mineral deficiencies, which can be minimized with careful management
(119). In addition, after surgery, patients are no longer able to eat in the way they were accustomed to. Those who have undergone gastric bypass experience “dumping syndrome” (sweating, palpitations, lightheadedness, nausea) if they ingest significant amounts of calorically and osmotically dense food, and therefore become conditioned not to eat these foods. Patients who have had gastric restriction surgery are unable to eat more than a limited amount of food at a single sitting without vomiting, and thus must eat several small meals per day to maintain adequate nutrition. Patients also must understand that following surgery, lifelong medical surveillance is a necessity
(2).
The Swedish Obese Subjects study, a large-scale nonrandomized study of surgery versus conventional treatment, provided the most compelling evidence for the benefits of surgery. In that study, 1,600 patients followed for a mean duration of 4 years after surgery experienced much greater sustained weight loss and a lower incidence of diabetes mellitus compared to control subjects. Unlike patients receiving conventional treatment, the surgical patients also reported dramatic short-term and sometimes long-term improvements in health-related quality of life
(86). However, most reports suggest that 20%–30% of the patients were unimproved in the long term
(119,
120). It is possible for patients to eat in a way that maintains their preoperative weight or to be unable to adapt to the limitations imposed by surgery, e.g., to repeatedly eat to the point of vomiting. We cannot yet predict with confidence which patients are likely to have poor outcomes, although some evidence has suggested that the presence of an eating disorder before surgery
(121,
122) or history of inpatient psychiatric treatment
(123) predict less favorable outcome.
Psychotherapy
Psychotherapy should not be considered a primary treatment for obesity. However, this does not mean that psychotherapy has no role. Both cognitive behavioral therapy and interpersonal therapy have been found to be effective in normalizing eating and reducing distress in obese patients with binge eating disorder, although neither intervention is associated with significant weight loss
(124). Psychotherapy may be helpful in enhancing self-acceptance in obese patients who have learned to feel ashamed about their weight and may help patients to cope with the effects of prejudice and “weightism” that are pervasive in our culture. Often, greater self-acceptance and the resulting increase in overall self-esteem are key steps in developing motivation for working toward a healthier lifestyle and/or for undertaking weight control treatment
(125). Body image therapy programs have been developed to help obese individuals alter the way they perceive and evaluate their bodies
(126). These interventions are crucial for many obese patients, because most such patients, even after successful weight loss treatment, remain at a higher-than-normal weight. Self-help organizations that promote size acceptance provide recognition and support for obese individuals and serve as a forum for addressing discrimination and altering harmful cultural stereotypes.