An increase in
dietary protein intake has been shown to improve
weight loss maintenance in the DIOGenes trial. Here, we analysed whether the source of the
dietary proteins influenced changes in
body weight, body composition, and cardiometabolic risk factors during the weight maintenance period while following an energy-restricted diet. 489
overweight or obese participants of the DIOGenes trial from eight European countries were included. They successfully lost >8% of
body weight and subsequently completed a six month weight maintenance period, in which they consumed an ad libitum diet varying in
protein content and glycemic index. Dietary intake was estimated from three-day food diaries. A higher
plant protein intake with a proportional decrease in animal
protein intake did not affect body weight maintenance or cardiometabolic risk factors. A higher
plant protein intake from non-cereal products instead of cereal products was associated with benefits for body weight maintenance and blood pressure. Substituting
meat protein for
protein from other animal sources increased
insulin and HOMA-IR (homeostasis model assessment of
insulin resistance). This analysis suggests that not only the amount of
dietary proteins, but also the source may be important for weight and cardiometabolic risk management. However, randomized trials are needed to test the causality of these associations.