Background: Recent evidence has related high levels of plasma branch-chained amino acids (BCAAs) with liver and visceral fat. We examined the associations of plasma BCAAs with liver fat and abdominal fat distribution and assessed the potential modification of weight-loss diet interventions on these relations.

Methods: The current study included 184 participants with available data on plasma BCAAs, hepatic fat and abdominal fat distribution over 2 years, who were randomly assigned to 1 of 4 diets varying in macronutrient components.

Results: Decrease in plasma BCAAs after weight loss was significantly associated with improvement in hepatic density (a marker for hepatic fat; p=0.03) and reduction in visceral fat (p=0.01). We also found that a decrease in BCAAs was associated with decreased insulin, HOMA-IR, and triglycerides (p<0.05 for all). Moreover, we observed significant interactions between total plasma BCAAs and dietary protein on hepatic density (p-interaction=0.01). Individuals with a larger decrease in total BCAAs had a greater increase in hepatic density when consuming a high protein diet.

Conclusion: Our findings indicate that weight-loss diets decrease BCAAs, which are in turn associated with the reduction of hepatic and visceral fat. Finally, dietary protein modifies the direction of these associations.


X. Li: None. D. Sun: None. T. Zhou: None. G. Bray: Advisory Panel; Self; Herbalife International of America, Inc., Medifast. F. Sacks: None. L. Qi: None.


National Heart, Lung, and Blood Institute (HL0791981, HL034594, HL126024); National Institute of Diabetes and Digestive and Kidney Diseases (DK115679, DK091718, DK100383, DK078616); Boston Nutrition Obesity Research Center (DK46300); United States-Israel Binational Science Foundation (2011036); American Heart Association (0730094N to L.Q.)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at