The world’s growing obesity crisis is rarely out of the headlines, given the increasing burden on the healthcare system and the livelihoods of those affected. The abundance of highly calorific foods and aggressive marketing is often blamed, however new research seeks to provide quantifiable evidence of the relationship between obesity and multiple triggers.

The multidisciplinary research addresses environmental and biological issues, seeking to uncover what makes some people more likely than others to respond to such environmental triggers, why people over-eat in spite of the internal signals that control feelings of hunger and satiety, and the impact of our underlying genetic make-up and hormonal activity.

Leading the study is Dr Elanor Hinton, from the School of Clinical Sciences, who has been granted a fellowship by the Elizabeth Blackwell Institute for Health Research. Her interests centre on in what motivates people to eat excessively, the reward value of eating and discovering the difference that scientific research can make to changing eating behaviour. The research examines the processes underlying the changes in weight that result from weight management programmes, to better understand which regions of the brain are involved and how they connect.

“Our hope is that the weight management programmes will prove successful and we’ll be able to understand precisely why certain changes are happening. I suspect there will be changes in both satiety perception and appetite hormones. Crucially, we hope to understand the processes in the brain that control these changes and whether they can lead to long term change.” - Dr Elanor Hinton

Measuring the brain's responses to weight management

The research is funded by the Bristol Nutrition Biomedical Research Unit, and Dr Hinton will work closely with physiologists, dieticians and childhood obesity consultants. Facilities at the University's Clinical Research and Imaging centre (CRIC) offer fMRI technology (functional Magnetic Resonance Imaging) to measure blood flow in the regions of the brain associated with satiety and appetite.

Four groups of up to 15 teenagers will be assessed over a period of six months. One group of overweight teenagers will be given a new tool called the Mandolean, which will show their rate of eating and levels of satiety whilst they are consuming a carefully selected healthy meal. Drawing on patients from Bristol’s Care of Childhood Obesity Clinic, another group who have a genetic mutation in the MC4 receptor found in the brain that has a proven link to obesity, will also be assessed for their response to the Mandolean weight management programme.

Measurements of the hormones peptide YY and ghrelin, also known to be involved in appetite, will be taken from the three experimental groups, along with fMRI scans to see the differences in neural activity alongside variations in perception of satiety and eating rate. Crucially, over the six month period, Dr Hinton and her colleagues will be able to track changes in the brain in response to the different weight management programmes.

While previous studies have demonstrated the role of these individual components in obesity, this is the first multidisciplinary study of its kind to apply neuroimaging techniques to track all of the components in tandem. As such, it could provide invaluable advances towards an effective solution to a condition that to date, has shown no signs of abating.