For years, unsuccessful dieters have tended to blame weight problems on their genes. New research suggests that there may be some truth in this, but it does not negate the importance of diet and exercise in weight management.

A team of scientists at the Peninsula Medical School in Exeter, England, reviewed genetic data on more than 38,000 white European children and adults. It was found that a specific variation of the FTO gene predisposed subjects to fatness (body fat levels) and type 2 diabetes. The link was apparent in those aged more than 7 years.

Around 15% of adults were found to have the FTO gene variation, and these tended to weigh 3 kg more, on average, than adults who did not express the gene variation. In addition, the ‘at risk’ adults were nearly 70% more likely to become obese and 40% more likely to develop diabetes, mainly because of higher body fat levels. The link between gene variation, obesity and type 2 diabetes was also found in a previous study by the Peninsula Medical School team, which compared the genes of 2000 UK diabetes patients with 3000 healthy individuals.

The existence of such a strong genetic link with obesity may explain why some people tend to gain weight throughout life despite their best efforts to eat healthily. However, as the researchers pointed out, it does not negate the importance of diet and exercise in weight management. "Certainly diet and exercise are very important factors in influencing obesity risk and regardless of your genetic makeup it remains important to try to eat sensibly and exercise," said Professor Frayling, the first author of the paper.

For more information see
Frayling TM et al (2007). A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity. Science Apr 12; [Epub ahead of print].

EUFIC related material
Diet-related diseases – Obesity
Diet-related diseases – Diabetes
Health & Lifestyle –Physical activity