Scientists knew that overweight mothers tend to have more overweight children. But is the same true for fathers? This week in Nature, Margaret Morris and her team demonstrated this effect in male rats, the first time it's been shown to work in males. The findings are another example of how non-genetic factors, like how much a parent eats, can have a biological impact on offspring. The researchers put one of their two groups of male rats on a high-fat diet, the other on a normal one. Unsurprisingly, the high-fat rats put on a lot of weight and began to show symptoms of type II diabetes, like insulin resistance and struggles with metabolizing glucose. And then there were their kids: