activation of brown adipose tissue in mice, through the use of the amino acid leucine, was investigated. brown adipose tissue has become a topic of interest in recent years, as activation of this tissue has been proposed as a potential target for obesity and type 2 diabetes treatment. this is because activation requires large amounts of energy, as well as circulating glucose, and stores of triglycerides. previous work involving brown adipose tissue activation focuses on drugs with a known beta-adrenergic stimulus, which is one method of activation of brown adipose tissue, but few focus on potential dietary treatment. in order to assess activation due to leucine, 18f-fdg uptake was measured using positron emission tomography after treatment with leucine. using an analysis method of calculating standardized uptake value and maximum standardized uptake value, the level of 18f-fdg uptake was quantified and used to judge activation. it was shown that leucine causes an additional increase to brown adipose tissue activation in a hyperglycaemic state. this finding opens the door for future research involving the method of action of leucine or testing if leucine treatment has the potential to treat hyperglycaemia.