Brown adipose tissue plays an important role in energy expenditure. The deficiency of the essential amino acid leucine has been linked with CREB/TRH pathway and regulation of energy expenditure and food intake. Here we investigated the effect of leucine deficient diet on interscapular brown adipose tissue (iBAT) in mice. Dixon imaging was performed to assess fat fraction changes within iBAT followed by RNA analysis. There was a decrease in fat fraction for leucine deficient diet fed mice together with increased UCP1 expression indicating that short term leucine deprivation leads to iBAT activation.