A US randomized clinical trial revealed that a low-fat plant-based diet is effective in reducing body weight and increasing insulin sensitivity and postprandial metabolism. A total of 244 participants with body mass index of 28 to 40 (87% female, 48% White, mean age 54.4 years) were randomized in a 1:1 ratio to the intervention group (n = 122, approximately 75% of energy from carbohydrates, 15% protein, and 10% fat, consisted of vegetables, grains, legumes, and fruits without animal products or added fats, supplemented with Vitamin B12 500 μg/d) and the control group (n = 122, no diet changes) for 16 weeks between January 2017 and February 2019. Hepatocellular and intramyocellular lipids were quantified in a subset of participants (n = 44). Over the 16 weeks, body weight decreased in the intervention group by 5.9 kg. Thermic effect of food increased in the intervention group by 14.1%. Two indexes of insulin resistance, the homeostasis model assessment index decreased, and the predicted insulin sensitivity index (PREDIM) increased in the intervention group. Hepatocellular and intramyocellular lipid levels decreased in the intervention group by 34.4% and 10.4%, respectively. None of these variables changed significantly in the control group over the 16 weeks. The change in PREDIM correlated negatively with the change in body weight. Changes in hepatocellular and intramyocellular lipid levels correlated with changes in insulin resistance. The findings are consistent with previous studies and suggest that a low-fat plant-based dietary intervention reduces body weight by reducing energy intake and increasing postprandial metabolism, apparently owing to increased insulin sensitivity resulting from reduced hepatocellular and intramyocellular fat. However, the study design did not allow separation of the specific effects of the vegan diet from the weight loss it causes. Source: https://jamanetwork.com/
