Dr. Tony Goldstone, Imperial College London, uses magnetic resonance imaging (MRI) of the brain to identify how obesity, gut hormones and treatments for obesity modify the structure and function of the brain. Projects examine the effects of being hungry (e.g. when fasted compared to having eaten a meal), gut hormones (e.g. when given an injection of a hormone that alters appetite), obesity itself, and different diets or surgical treatments for obesity (e.g. gastric bypass and gastric banding). Studies look at the changes in the structure of the brain, how the brain responds to food, addictive behaviours that promote overeating, and what type of foods people prefer (e.g. high-calorie sugary/fatty or low-calorie foods). Participants have brain scans while performing various computerised tasks such as looking at food pictures, complete questionnaires about their eating habits, measurements of their appetite and hormones, and analysis of their DNA to look at genetic variations that predispose to obesity. Many participants also have whole body MRI scans to look at how much fat they have in their body and where it is located. Discoveries include finding that:
- skipping breakfast biases brain reward systems to high-calorie foods,
- the stomach hormone ghrelin mimics fasting to increase brain activation to food, and
- patients after gastric bypass surgery for obesity have healthier eating habits, find high-calorie foods less appealing and have less brain activation to food than those who have had gastric banding surgery, possibly related to increases in the release of the hormones GLP-1 and PYY from the bowel. These studies help identify the causes of obesity, the mechanisms by which bariatric surgery works, new targets for treatment of obesity, novel ways of assessing their effectiveness, and which treatments best suit which patients.
PI: Dr. Tony Goldstone