Effects of different protein content and glycaemic index of ad libitum diets on diabetes risk factors in overweight adults: the DIOGenes multicentre, randomized, dietary intervention trial

Diabetes Metab Res Rev. 2011 Oct;27(7):705-16. doi: 10.1002/dmrr.1218.


Background: Dietary regimens providing different levels of protein and glycemic index (GI) foods when prescribed for weight management may also influence insulin sensitivity.

Procedures and outcomes: Overweight/obese adults in 8 European countries who lost ≥ 8% of initial body-weight (BW) after following a low calorie diet (LCD) were later randomly assigned with a 2x2 factorial design into 4 ad libitum dietary groups with two different protein content levels and dissimilar glycemic index, which were compared to a healthy reference diet. Specific markers assessing insulin resistance were measured. The LCD was initially applied to 932 adults and 773 were randomised to the 5 ad libitum diets. The 6-months programme was completed by 548 participants. The assignment to the Low Protein /High Glycemic Index diet induced a statistically higher HOMA-IR increase during the 6 months period as compared to the control. Contrariwise, the insulin response was lower in the High Protein/Low Glycemic Index diet after 60 and 90 min of an Oral Glucose Tolerance test subsequently carried out after the 6-months intervention. The Low Glycemic Index diets (either with high or low protein content) also lead to a decrease in fructosamine levels during the trial.

Conclusion/interpretation: After a weight loss period, an increase in the dietary protein proportions and a decrease in the consumption of foods with a high Glycemic Index within an ad libitum dietary intervention aiming to weight maintenance produced favorable effects on glycaemic control and insulin sensitivity in overweight/obese subjects.

Keywords: diabetes; diet; energy restriction; high-protein diets; insulin resistance; low glycaemic index diets; obesity; weight loss; weight maintenance.

Publication types

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

MeSH terms

  • Adult
  • Body Mass Index
  • Body Weight
  • Diabetes Mellitus, Type 2 / diet therapy
  • Diabetes Mellitus, Type 2 / etiology*
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Diet
  • Dietary Proteins*
  • Female
  • Glycemic Index*
  • Humans
  • Insulin Resistance
  • Male
  • Middle Aged
  • Overweight / complications*
  • Overweight / diet therapy
  • Risk Factors


  • Dietary Proteins