Washington: Men, you should think about shedding those extra kilos before starting a family as a new study has suggested that doing so can lower the risk of your children being fat.
The study reveals that a man's weight affects the heritable information contained in sperm. The sperm cells of lean and obese men possess different epigenetic marks, notable at gene regions associated with the control of appetite.
The comparisons, which included 13 lean men and 10 obese men, offer one biological explanation for why children of obese fathers are themselves more predisposed to obesity.
In the next phase of the study, the investigators tracked 6 men undergoing weight-loss surgery to see how it affected their sperm. An average of 5,000 structural changes to sperm cell DNA were observed from the time before the surgery, directly after, and one year later.
More needs to be learned about what these differences mean and their effects on offspring, but it is early evidence that sperm carries information about a man's health.
The research could lead to changing behavior, particularly pre-conception behavior of the father, says senior author Romain Barres of the University of Copenhagen.
"It's common knowledge that when a woman is pregnant she should take care of herself, not drink alcohol, stay away from pollutants, etc., but if the implication of our study holds true, then recommendations should be directed towards men, too."
There are likely evolutionary reasons why information about a father's weight would be valuable to offspring. Barres theory is that in times of abundance, it's an instinctual way to encourage children to eat more and grow bigger.
"It's only recently that obesity is not an advantage," he says. "Only decades ago, the ability to store energy was an advantage to resist infections and famines."
"It is clear that these epigenetic changes happen in mice and rats," Barres says, "but we also need to know if this also happens in humans and whether this is a significant driver for changing our traits."
The study is published in Cell Metabolism.
