What lies behind the causal impact of body mass index (BMI) level and change on human health? Added value from complementary study design and deep metabolomic phenotyping

Body mass index (BMI) is a simplified measure of body composition/fatness based on your weight adjusted for height and there are clear correlations between BMI and health. However, it is extremely difficult to change BMI in many people and we still do not understand why BMI is a risk factor.The processes of our bodies leave behind chemical biproducts which can be measured easily and efficiently to provide a snapshot of health status. The relationships between these ‘metabolites’ and BMI can help understand the biological implications of different body sizes.

Using collections of metabolites measured in very different studies, I will characterise the effects of BMI on a broad range of biological processes. I will then use very large studies of the general population to bring together evidence and generate a list of metabolites which are affected by BMI. Once done, I will use publicly available genetic studies of disease to find out if BMI has an effect on metabolites and what this does to the risk of disease. 

This will inform future work that looks closely at metabolites that do alter disease risk, rather than attempting to change BMI alone.