Study Compares Two Weight Loss Therapies in Overweight/Obese Veterans
Studies comparing low-carbohydrate diets with reduced-calorie diets have shown that weight loss can be greater on a low-carbohydrate diet. In addition, two weight loss medications approved for long-term use - orlistat (now available without Rx) and sibutramine - when paired with a reduced-calorie diet, have proven more effective than diet alone. But neither of these medications has been compared with a low-carbohydrate diet. This study compared a low-carbohydrate, ketogenic diet (LCKD) to orlistat combined with a low-fat, reduced-calorie diet (O+LFD). Investigators assessed body weight, metabolic, and adverse effects over 48 weeks in overweight or obese Veterans who received VA outpatient care between 4/05 and 10/06 and were randomized to either diet intervention - LCKD (n=57) or O+LFD (n=65). Both diet interventions incorporated group meetings that included study measurements and counseling.
Findings show that a low-carbohydrate diet led to similar improvements as orlistat plus a low-fat diet for weight, serum lipid, and glycemic parameters - and was more effective for lowering blood pressure. While weight loss was significant and similar for both diet interventions, and decrease in waist circumference also was similar, the LCKD had a more beneficial impact than the O+LFD on systolic (-5.9 vs. 1.5 mm Hg) and diastolic (-4.5vs. 0.4 mm Hg) blood pressure. Study results also show that participants who attended 80% or more of the group counseling sessions lost considerably more weight, regardless of treatment assignment. The authors suggest that efforts be made to incorporate similarly intensive weight loss programs into medical practice.
Yancy Jr. W, Westman E, McDuffie J, et al. A Randomized Trial of a Low-Carbohydrate Diet Versus Orlistat Plus a Low-Fat Diet for Weight Loss. Archives of Internal Medicine January 25, 2010;170(2):136-45.
This study was funded by VA. Dr. Yancy also was supported by an HSR&D Career Development Award. All authors except Dr. Westman are part of HSR&D's Center for Health Services Research in Primary Care located in Durham, NC.