Reducing the dietary glycemic load and the glycemic index was proposed as a novel approach to weight reduction. A parallel-design, randomized 12-wk controlled feeding trial with a 24-wk follow-up phase was conducted to test the hypothesis that a hypocaloric diet designed to reduce the glycemic load and the glycemic index would result in greater sustained weight loss than other hypocaloric diets. Obese subjects (n = 29) were randomly assigned to 1 of 3 diets providing 3138 kJ less than estimated energy needs: high glycemic index (HGI), low glycemic index (LGI), or high fat (HF). For the first 12 wk, all food was provided to subjects (feeding phase). Subjects (n = 22) were instructed to follow the assigned diet for 24 additional weeks (free-living phase). Total body weight was obtained and body composition was assessed by skinfold measurements. Insulin sensitivity was assessed by the homeostasis model (HOMA). At 12 wk, weight changes from baseline were significant in all groups but not different among groups (-9.3 +/- 1.3 kg for the HGI diet, -9.9 +/- 1.4 kg for the LGI diet, and -8.4 +/- 1.5 kg for the HF diet). All groups improved in insulin sensitivity at the end of the feeding phase of the study. During the free-living phase, all groups maintained their initial weight loss and their improved insulin sensitivity. Weight loss and improved insulin sensitivity scores were independent of diet composition. In summary, lowering the glycemic load and glycemic index of weight reduction diets does not provide any added benefit to energy restriction in promoting weight loss in obese subjects.

OBJECTIVE -The purpose of this study was to evaluate the effects of a combination weight loss program using intermittent low-calorie diets, energy-controlled meal replacement products, and sibutramine on weight loss, diabetes control, and cardiovascular risk factors in overweight or obese subjects with type 2 diabetes.RESEARCH DESIGN AND METHODS -Overweight or obese individuals with type 2 diabetes treated with diet or oral medication were randomly assigned to either a standard therapy or combination therapy group. Both groups received a standardized program to facilitate weight loss. The combination therapy group also received 10 -15 mg sibutramine daily, low-calorie diets using meal replacement products for 1 week every 2 months, and between low-calorie diet weeks, once daily use of meal replacement product and snack bars to replace one usual meal and snack. Primary outcome measures were changes in body weight, glycemic control, plasma lipids, blood pressure, pulse, and body composition at 1 year.RESULTS -At 1 year, combination therapy, compared with standard therapy, resulted in significantly more weight loss (Ϫ7.3 Ϯ 1.3 kg vs. Ϫ0.8 Ϯ 0.9 kg, P Ͻ 0.001) and reduction in HbA 1c (Ϫ0.6 Ϯ 0.3 vs. 0.0 Ϯ 0.2%, P ϭ 0.05). Combination therapy resulted in reduced requirement for diabetes medications and decreased fat mass and lean body mass. A 5-kg decrease in weight at 1 year was associated with a decrease of 0.4% in HbA 1c (P ϭ 0.006). Changes in fasting glucose, lipids, pulse, and blood pressure did not differ between groups.CONCLUSIONS -This combination weight loss program resulted in greater weight loss and improved diabetes control compared with a standard weight loss program in overweight or obese subjects with type 2 diabetes.

OBJECTIVE -To evaluate the effects over 2 years of a weight loss program combining several weight loss strategies on weight loss and diabetes control in overweight subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS-A total of 59 overweight or obese individuals with type 2 diabetes were randomly assigned to either a combination therapy weight loss program for 2 years (C therapy) or a standard therapy weight loss program for 1 year followed by a combination therapy weight loss program in the 2nd year (S/C therapy). C therapy combined the use of meal replacement products, repetitive intermittent low-calorie-diet weeks, and pharmacologic therapy with sibutramine. Outcome measures included changes in weight, glycemic control, plasma lipids, blood pressure, and body composition over 2 years.RESULTS -A total of 48 participants (23 in the C therapy group and 25 in the S/C therapy group) completed 2 years of study. After 2 years, the C therapy group had weight loss of 4.6 Ϯ 1.2 kg (P Ͻ 0.001) and a decrease in HbA 1c of 0.5 Ϯ 0.3% (P ϭ 0.08) from baseline. At 2 years, the C therapy group had significant reductions in BMI, fat mass, lean body mass, and systolic blood pressure. The S/C therapy group showed changes in weight and HbA 1c in year 2 of the study that were similar to those demonstrated by the C therapy group in year 1.CONCLUSIONS -This combination weight loss program resulted in significant weight loss and improved diabetes control over a 2-year period in overweight subjects with type 2 diabetes. Diabetes Care 28:1311-1315, 2005W eight loss is an important therapeutic objective for individuals with type 2 diabetes (1). Shortterm studies have demonstrated that weight loss in overweight or obese type 2 diabetic subjects is associated with decreased insulin resistance, improved measures of glycemic control, reduced lipemia, and reduced blood pressure (2-4). However, the most recent American Diabetes Association nutrition recommendations concluded that "optimal strategies for preventing and treating obesity long term have yet to be defined" (5).Long-term options to promote weight loss in people with type 2 diabetes include standard weight-reduction diets and very-low-calorie diets. However, standard weight-reduction diets are usually not effective (5). Very-low-calorie diets produce substantial initial weight loss but do not maintain weight loss long term (6).Other approaches to weight loss that might be effective in type 2 diabetic subjects include use of meal replacements, repetitive use of low-calorie diets, and weight loss medications. Hensrud (7) reported significant weight loss at 3 months using meal replacements in type 2 diabetic subjects, but weight and measures of glycemic control trended toward baseline values at 1 year. Williams et al. (8) compared a standard diet to very-low-calorie diets used either 1 day per week or 5 consecutive days every 5 weeks in type 2 diabetic subjects. After 15 weeks, the verylow-calorie diet groups lost 9.6 and 10.4 kg, respectively, compared with weight loss of 5.4 k...