South Beach Diet™ Research

A randomized, controlled clinical trial to evaluate the efficacy of a modified carbohydrate diet for reducing body weight and fat in overweight and obese men and women

Kevin C. Maki1, Tia M. Rains2, Valerie N. Kaden1, Judy Quinn1, Michael H. Davidson1: 1Radiant Research, 515 N. State Street, Suite 2700, Chicago, IL 60610, 2Kraft Foods, 801 Waukegan Rd., Glenview, IL 60025

Objective. This randomized, controlled trial assessed the effects of a modified carbohydrate diet (MCD) on body weight and fat in overweight and obese men and women.

Methods. Eighty-seven subjects, 18 to 65 years of age, with waist >= 87 cm (females) or >= 90 cm (males) were randomly assigned to consume a MCD or a low-fat, portion-controlled diet (control). MCD subjects were instructed on maintaining a low-carbohydrate intake (~40 g/d) during weeks 0-2, then to incorporate low glycemic index carbohydrates back into their diets during weeks 2-12, and to eat until satisfied. Control subjects were instructed to reduce fat intake and decrease portion sizes, with a targeted energy deficit of 500-800 kcal/d.

Results. Sixty-nine subjects completed to week 12. Glycemic load was reduced to a greater extend at week 12 in the MCD group (-51% vs. -11%, p < 0.001), which also showed greater mean loss of body weight (4.8 vs. 2.7 kg, p = 0.006) and fat (2.0 vs. 1.1 kg, p = 0.04) than controls. MCD subjects had significant improvements vs. controls in fasting triglycerides (-16.5 vs. -5.0 mg/dL; p = 0.045) and the total/HDL cholesterol ratio (-0.22 vs. -0.01, p = 0.03).

Conclusion. During a 12-week treatment period, a MCD yielded greater losses of body weight and fat, as well as improvements in serum triglycerides and the total/HDL cholesterol ratio compared to a traditional low-fat, portion-controlled diet.

Funded by Kraft Foods, Inc.