Researchers at UCL Centre for Obesity Research, led by Professor Rachel Batterham, are using brain imaging to gain a greater understanding of how the brain controls taste and appetite with the aim of developing novel approaches to treat obesity, which now affects one in four adults in the UK. An improved understanding of bodyweight control is needed to develop new, effective treatments for obesity.
It is already known that brain structure and connections within the parts of the brain that control eating can be affected by changes in weight. These weight-related changes may affect people’s appetite, their food preferences and their sense of taste.
After weight loss surgery – currently the most effective treatment for people with severe obesity –eating habits and food preferences change, meaning patients are less hungry and find healthier foods such as salads and fruit more appealing. The reasons why these changes occur are unknown but are thought to be related to changes in appetite-controlling hormones and the way these act on brain networks controlling taste, appetite and eating. It is also not yet known if these changes happen as a direct result of surgery - or because of weight loss.
The Taste and Eating Behaviour study (TASTER) study, will evaluate the effect of sleeve gastrectomy (SG) - the most common weight loss surgery where a large part of the stomach is removed - on brain structure and the brain networks that control appetite and taste. Participants will undergo brain functional magnetic resonance imaging (fMRI) while tasting liquid foods: before and after losing weight.
“We know that weight loss surgery changes appetite and taste. But we don’t yet fully understand how weight loss surgery leads to these changes.”
In addition, blood and saliva samples will be collected to measure levels of appetite-controlling hormones, and participants will be asked to rate their appetite and how much they like the foods they taste. This will shed light on connections between brain activity, appetite-controlling hormones and how people perceive the food they eat.
A group of participants with severe obesity losing weight through a low calorie diet will undergo the same assessments. Both groups of participants will undergo the same assessments after having lost a comparable amount of weight, in order to determine if any changes in brain responses observed are due to weight loss per se or as a direct result of weight loss surgery.
The results from both groups will also be compared to results from a group of normal weight participants who undergo the same assessments.
Dr Makaronidis from the Centre of Obesity research said: “We know that weight loss surgery changes appetite and taste. But we don’t yet fully understand how weight loss surgery leads to these changes.”
"Improving our understanding of how body weight is controlled and how weight loss surgery works, will help development of new more effective treatments for people living with obesity."
Any questions relating to the TASTER study can be directed to j.makaronidis@ucl.ac.uk.
