Weight Loss Maintenance in Overweight Subjects on Ad Libitum Diets With High or Low Protein Content and Glycemic Index: The DIOGENES Trial 12-month Results

Int J Obes (Lond). 2014 Dec;38(12):1511-7. doi: 10.1038/ijo.2014.52. Epub 2014 Mar 28.

Abstract

Background: A high dietary protein (P) content and low glycemic index (LGI) have been suggested to be beneficial for weight management, but long-term studies are scarce.

Objective: The DIOGENES randomized clinical trial investigated the effect of P and GI on weight loss maintenance in overweight or obese adults in eight centers across Europe. This study reports the 1-year results in two of the centers that extended the intervention to 1 year.

Method: After an 8-week low-calorie diet (LCD), 256 adults (body mass index >27 kg m(-)(2)) were randomized to five ad libitum diets for 12 months: high P/LGI (HP/LGI), HP/high GI (HP/HGI), low P/LGI (LP/LGI), LP/HGI and a control diet. During the first 6 months, foods were provided for free through a shop system and during the whole 12-month period, subjects received guidance by a dietician. Primary outcome variable was the change in body weight over the 12-month intervention period.

Results: During the LCD period, subjects lost 11.2 (10.8, 12.0) kg (mean (95% confidence interval (CI))). Average weight regain over the 12-month intervention period was 3.9 (95% CI 3.0-4.8) kg. Subjects on the HP diets regained less weight than subjects on the LP diets. The difference in weight regain after 1 year was 2.0 (0.4, 3.6) kg (P=0.017) (completers analysis, N=139) or 2.8 (1.4, 4.1) kg (P<0.001) (intention-to-treat analysis, N=256). No consistent effect of GI on weight regain was found. There were no clinically relevant differences in changes in cardiometabolic risk factors among diet groups.

Conclusion: A higher protein content of an ad libitum diet improves weight loss maintenance in overweight and obese adults over 12 months.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Body Weight
  • Caloric Restriction
  • Diet, Protein-Restricted
  • Diet, Reducing*
  • Dietary Carbohydrates / administration & dosage
  • Dietary Proteins / administration & dosage*
  • Energy Intake
  • Europe / epidemiology
  • European Continental Ancestry Group*
  • Family
  • Female
  • Glucose Tolerance Test
  • Glycemic Index*
  • Humans
  • Male
  • Nutrition Surveys
  • Obesity / prevention & control
  • Obesity / therapy*
  • Patient Compliance
  • Time Factors
  • Waist Circumference
  • Weight Gain*
  • Weight Loss*

Substances

  • Dietary Carbohydrates
  • Dietary Proteins