Obesity linked to grandparental diet

From Nature:

You are what you eat, and so are your progeny and, perhaps, your progeny's progeny — at least, if you're a mouse. According to research presented at the Society for Neuroscience's 38th annual meeting in Washington DC held from 15–19 November, mice fed on a high-fat diet throughout their pregnancies and suckling had offspring that were larger than normal — a trait that was also passed on to their offspring's offspring. It is the first time that a gestating mother's diet has been shown to confer this trait on to two consecutive generations.

The work is part of a larger study being conducted by neuroscientist Tracy Bale and her colleagues at the University of Pennsylvania in Philadelphia. "We wanted to know if the current increase in rates of obesity we are seeing all over the United States could have a longer-term impact," says Bale. The mice descended from mothers on the high-fat diet were about 20% heavier than those descended from mothers kept on normal food. They were not much fatter, but they were significantly longer. They also tended to overeat, whether or not they themselves were on a high-fat or normal diet. And they were insulin-insensitive, a feature of diabetes that frequently leads to obesity. Their own offspring — the second generation after the mothers on a fatty diet — did not overeat, but were large and insulin-insensitive. These traits were not just inherited through the female line: male pups born to mothers on a high-fat diet also transmitted them to their own offspring.

More here.