Mouse 'fat gene' gives clues on weight gain

“The secret to staying slim may be all in your genes,” the Daily Mail has today reported, adding that scientists have uncovered a “greedy gene that makes you eat more even when you are full”.

Before any dieters lose hope and reach for the nearest biscuit, it’s important to note that this news is based on research looking at a mutant gene in mice, not humans. The study examined the impact of a mutated gene called BDNF and the role it plays in telling the body it is full. Normally, various organs and tissues will use hormones to tell the brain that no more food is needed, causing the brain to suppress appetite. However, when mice carried a mutant version of the BDNF hormone it appeared this fullness mechanism was blocked, which meant they carried on eating and gaining weight. Male mice carrying the mutation became nearly twice as heavy as their non-mutant counterparts, while females were 2.7 times heavier.

This study may provide a springboard for further research into the role of genetics in the development of obesity. However, this study was carried out in mice and the findings cannot be assumed to apply to humans, whose bodies may react differently to any similar mutation. It’s also not clear how many humans actually carry similar mutations, so it should not be assumed that all obesity is down to genetics.