Weight Reduction

WEIGHT REDUCTION

Weight reduction can help reduce the complications of obesity, including T2D and hypertension. To achieve weight reduction, the obese patient must decrease energy intake or increase energy expenditure, although decreasing energy intake is thought to contribute more to inducing weight loss. Typically, a prescription for weight reduction combines dietary change; increased physical activity; and behavioral modification, which can include nutritional education and meal planning, recording and monitoring food intake through food diaries, modifying factors that lead to overeating, and relearning cues to satiety. Once weight loss is achieved, weight maintenance is a separate process that requires vigilance because the majority of patients regain weight after they stop their weight loss efforts.

A. Physical activity

An increase in physical activity can create an energy deficit. Although adding exercise to a hypocaloric regimen may not produce a greater weight loss initially, exercise is a key component of programs directed at maintaining weight loss. In addition, physical activity increases cardiopulmonary fitness and reduces the risk of cardiovascular disease, independent of weight loss. Persons who combine caloric restriction and exercise with behavioral treatment may expect to lose about 5%–10% of initial body weight over a period of 4–6 months. Studies show that individuals who maintain their exercise program regain less weight after their initial weight loss.

B. Caloric restriction

Dieting is the most commonly practiced approach to weight control. Because 1 pound of adipose tissue corresponds to approximately 3,500 kcal, one can estimate the effect that caloric restriction will have on the amount of adipose tissue. Weight loss on calorie-restricted diets is determined primarily by energy intake and not nutrient composition. [Note: Compositional aspects can, however, affect glycemic control and the blood lipid profile.] Caloric restriction is ineffective over the long term for many individuals. More than 90% of people who attempt to lose weight regain the lost weight when dietary intervention is suspended. Nonetheless, it is important to recognize that, although few individuals will reach their ideal weight with treatment, weight losses of 10% of body weight over a 6-month period often reduce blood pressure and lipid levels and enhance control of T2D. The health benefits of even relatively small weight losses should, therefore, be emphasized to the patient.

C. Pharmacologic treatment

Several weight-loss medications are currently approved by the U.S. Food and Drug Administration for use in adults with a BMI of 30 or higher. Three approved for long-term use are: 1) orlistat (decreases absorption of dietary fat), 2) lorcaserin (promotes satiety), and 3) a combination of phentermine (suppresses appetite) and extended-release topiramate (controls seizures). [Note: Phentermine monotherapy is approved for short-term use only.] Their effects on weight reduction tend to be modest, and weight regain upon termination of drug therapy is common.

D. Surgical treatment

Gastric bypass and restriction surgeries are effective in causing weight loss in severely obese individuals. Through mechanisms that remain poorly understood, these operations greatly improve poor blood sugar control in morbidly obese diabetic individuals.