Changes of Branched-Chain Amino Acids and Ectopic Fat in Response to Weight-loss Diets: the POUNDS Lost Trial

Abstract

Context Recent evidence has related circulating branch-chained amino acids (BCAAs) to ectopic fat distribution. Objective To investigate the associations of changes in plasma BCAAs induced by weight-loss diet interventions with hepatic fat and abdominal fat, and potential modification by different diets. Design, Setting, and Participants The current study included 184 participants from the 2-year Preventing Overweight and Using Novel Dietary Strategies (POUNDS Lost) trial with repeated measurements on plasma BCAAs, hepatic fat, and abdominal fat over 2 years. Main Outcome Measures Repeated measurements of hepatic fat, abdominal fat distribution, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT). Results Over 2 years, a decrease in total plasma BCAAs was significantly associated with improvement in hepatic density (a marker for hepatic fat; p=0.02) and reductions in abdominal fat, including VAT, SAT, and TAT (all ppp-interaction=0.01). Participants with a larger decrease in total BCAAs showed a greater increase in hepatic density when consuming a high-protein diet, compared to those with a smaller decrease or increase in total BCAAs. Conclusions Our findings indicate that weight-loss diet induced-decrease in plasma BCAAs is associated with reductions of hepatic and abdominal fat. In addition, dietary protein intake may modify these associations.