Presentation Abstract

Session: 10-B-Outcomes
Friday, Mar 25, 2011, 10:30 AM -12:00 PM
Presentation: 049 - Can You Keep it off? 18 Month Follow-Up after a Two-Year Dietary Intervention Randomized Trial of Low-Carbohydrate, Mediterranean or Low-Fat Diets (Direct)
Location: Marquis Ballroom AB
Pres. Time: Friday, Mar 25, 2011, 11:45 AM -12:00 PM
Category: +NPAM - Preventive Cardiology/Clinical Trials
Keywords: Diet; Clinical trials; Obesity
Author(s): Iris Shai, Harvard Sch of Public Health, Boston, MA; Harel Segal, Nuclear Res Ctr Negev, Dimona, Israel; Rachel Golan, Yftach Gepner, Osnat Tangi-Rosental, Ben Gurion Univ, Beer Sheva, Israel; Meir J Stampfer, Harvard Sch of Public Health, Boston, MA; Dan Schwarzfuchs, Nuclear Res Ctr Negev, Dimona, Israel
Abstract: Introduction: Trials comparing different weight-loss diets are frequently limited to the intervention period. Evidence of long term efficacy is sparse.
Hypothesis: Regain was expected.
Methods: In a 2-year intervention trial (DIRECT), we randomly assigned 322 moderately obese subjects (age:52 years; BMI:31kg/m2; 86% male) to low-fat or Mediterranean, restricted-calorie; or low-carb without caloric restriction. We further followed participants for 18 months without any further intervention.
Results: 18 months after the intervention ended, 67% of the participants continued with their original assigned diet, 11% switched to another diet and 22% were not dieting (p=0.36 between diet-groups). By the end of the trial, participants lost an average of 4kg, and regained 1.23kg 18 months later (p=0.25 between groups). Regain (Fig1) was observed in men only (+1.51kg vs. -0.64kg in women; p=0.04). Compared to pre-intervention baseline, 18 months after the end of intervention, total weight loss was 2.5 kg for low-fat, 5.4 for Mediterranean and 4.5kg for low-carb (p=0.04 between groups).There was a significant (p<0.05) continued decrease in LDL-c levels of -3.83mg/dL (p=0.58 between groups), and partial, non-significant, increase of TG (+8.31 mg/dL;p=0.51 between groups) and decrease in HDL-c (-0.72mg/dL;p=0.61 between groups). However, HDL-c continued to increase in the Mediterranean diet. As compared to baseline, 42 months back, significant improvements were persistent in TG and HDL-c levels (Mediterranean and low-carb diets), in LDL-c (Mediterranean and low-fat diets) and overall reduction in LDL-c to HDL-c ratio and total weight (low-fat, Mediterranean and low-carb diets);p<0.05 for all.
Conclusions: This long-term intervention trial had a persistent effect on improved metabolic parameters, despite partial regain of weight. LDL-c is reduced in long-term healthy diets. As compared to low-fat diet, Mediterranean and low-carb diets are apparently more effective, and the Mediterranean diet seemed to be more stable.
Disclosures:  I. Shai: None. H. Segal: None. R. Golan: None. Y. Gepner: None. O. Tangi-Rosental: None. M.J. Stampfer: None. D. Schwarzfuchs: None.