A low-fat, plant-based diet increases "after-meal burn" and improves body weight and insulin sensitivity, according to a study by Physicians Committee researchers published in JAMA Network Open. Participants followed either a low-fat, vegan diet or made no dietary changes for 16 weeks. Researchers tracked body weight, body fat composition, insulin sensitivity, and the thermic effect of food at assessments at baseline and the end of study. The authors tracked intramyocellular lipid and hepatocellular lipid—the accumulating fat in muscle and liver cells that contributes to insulin resistance in a subset of participants. Those in the vegan group lowered their body weight by 6.4 kg (about 14 pounds) and the fat inside the liver and muscle cells by 34% and 10%, respectively, and increased their metabolism by 18.7% compared to no significant changes in the control group.
Kahleova H, Petersen KF, Shulman GI, et al. Effect of a low-fat vegan diet on body weight, insulin sensitivity, postprandial metabolism, and intramyocellular and hepatocellular lipids in overweight adults: a randomized clinical trial. JAMA Netw Open. 2020;3(11):e2025454-e2025468. doi:10.1001/jamanetworkopen.2020.25454