Studying the Effect of Capsinoids on Brown Fat Using Infrared Thermal Imaging.

It has been recently established that brown adipose tissue (BAT) exists in adult humans. BAT is a thermogenic tissue which dissipates energy as heat. The primary objective of this study is to use thermal imaging to assess the effect of capsinoids on BAT activity in adult humans, and whether there is a relationship between the increase in energy expenditure and BAT activity after capsinoids intake. The secondary objective is to investigate whether capsinoids will have an effect on an individual's glycaemic response. Lean, healthy male volunteers will be recruited. There will be two test sessions which are randomized, where subjects will consume either capsinoids or placebo capsules, and a standardized amount of white rice (equivalent to 50g carbohydrates). Indirect calorimetry will be used to assess energy expenditure before and after consumption of the test meal. Thermal imaging of supraclavicular BAT, the primary BAT depot in humans, will be undertaken using an infrared thermal camera to assess changes in BAT temperature. Blood glucose levels will be monitored by finger prick blood sampling method. This study aims to investigate whether capsinoids consumption leads to changes in BAT temperatures detectable by the infrared thermal camera, to confirm the feasibility of using thermal imaging as a rapid, noninvasive, and reproducible way of studying BAT activity thus providing a platform to advance research in this emerging field of human BAT.

Inclusion criteria

• Chinese ethnicity
• Male
• Healthy
• Age 21 - 30 years
• BMI 18.0 - 22.9 kg/m2
• Not on any prescribed medication
• Infrequent spicy food or chilli user (less than 3 times per week)

Exclusion criteria

• Smoker
• Fasting blood glucose > 5.5 mmol/L
• Resting blood pressure > 140/90 mmHg
• Any major medical conditions including diabetes, hypertension, cardiovascular disease, thyroid disorders
• Allergic or intolerant to foods presented in the study