In September 2018 researchers from the USA published the results of their study to assess the role of plant protein on body composition and insulin resistance in overweight individuals. A total of 75 individuals were involved in the study, with 38 consuming a plant-based vegan diet and 37 a control diet. Body composition and insulin resistance was assessed at the start of the study and again after a 16-week period. Results showed that the plant-based vegan diet proved to be superior to the control diet in improving body weight, fat mass, and insulin resistance. Only the vegan group showed significant reductions in body weight, fat mass and insulin resistance. The decrease in fat mass was associated with an increased intake of plant protein and decreased intake of animal protein. In particular, a decreased leucine intake was associated with a decrease in fat mass, and a decrease in histidine an improvement in insulin resistance, which was irrespective of changes in BMI.
Kahleova H et al. A plant-based diet in overweight individuals in a 16-week randomized clinical trial: metabolic benefits of plant protein. Nutr Diabetes. 2018 Nov 2;8(1):58.