Solving a slimming diet mystery

There is a popular idea that some people can eat almost anything and yet always remain slim while others among us only have to look at fattening foods to gain weight.

This belief has been given some credence by recent research.

According to a report published in the July 2010 issue of Genetics, US researchers using fruit flies have discovered that an interaction between genes and diet, rather than just diet alone, could be the main cause of increased body weight.

The researchers studied 146 different genetic lines of fruit flies that were fed four different diets. It was found that flies in some of the genetic lines were highly sensitive to their diets, and this was reflected in changes in body weight. But flies of other genetic lines showed no change in weight across diets.

The contribution of genetics alone, diet alone or the interaction between genotype and diet was measured. Results showed that diet alone made a small contribution to the total variation, while genotype and genotype interactions with diet made large contributions.

This study, if it were to be replicated in humans, suggests that some individuals can achieve benefits from altering their dietary habits, while the same changes for others will have practically no effect.

It is a nice thought, but this is certainly a case where further evidence is needed.