A Role for Brown Adipose Tissue in Postprandial Thermogenesis?

Study Overview
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Brief Summary
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Brown adipose (fat) tissue (BAT) is a type of fat tissue found in certain small rodents and human babies that is capable of extremely high rates of energy burning. We now know that in adult humans it is present and also able to burn energy. In addition to increased energy expenditure during cold exposure, energy burning is also increased after consuming a meal. Animal studies have shown that part of this additional energy consumption is contributed by BAT. In the present study we will aim to examine whether BAT activity is increased after a meal.

Detailed Description
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The purpose of this project is to measure whether BAT activity (during which BAT increases energy burning) increases in response to ingestion of a meal. BAT is one of two types of fat, (the other being white fat), which is found in humans and other mammals. In this study we aim to further our understanding of how BAT works in humans. Studies in animals show that in addition to cold exposure, BAT is also activated by ingestion of a meal, and to different amounts depending on the meal composition, and more importantly, total energy content. However we have only a very limited understanding of BAT function in response to meals in humans. Since BAT function is defective in obesity, and its activity and function are impacted by diet, here we will find out whether a single high energy meal composed entirely of lipid (fat) can increase BAT activity. In future these findings and those of subsequent studies may have important implications for the management of obesity and related diseases. A total of 20 people will participate in this project. Participation will involve a total of 3 visits, including a screening visit, 2 experimental visits consumption of the treatment meal on one visit, and the placebo (dummy) on the other in a randomised order.

Official Title
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A Role for Brown Adipose Tissue in Postprandial Thermogenesis?

Conditions
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Obesity, Diabetes, Cardiovascular Disease

Intervention / Treatment
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* Dietary Supplement: Meal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males aged 19 - 35 years Unmedicated for the previous 2 months No major illness BMI 17-40 kg/m2 Exclusion Criteria: Unable to give informed consent Smokers Participant in research projects involving ionising radiation within the past 5 years, excluding dual energy x-ray absorptiometry scans conducted in prior studies Claustrophobia Fasting plasma glucose > 6.0 mmol/L

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active<br>Meal | Dietary Supplement: Meal<br>* Meal<br>|
| Placebo Comparator: Control<br>Water | Dietary Supplement: Meal<br>* Meal<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| BAT activity | Analysis of PET/CT scans | 2 years |