Having trouble maintaining your ideal weight? Blame your dad's sperm. That may sound odd, but a study published Thursday in Cell Metabolism found that a man's weight may change the information carried in his sperm and predispose his children to obesity, reports the New York Times. Researchers compared epigenetic markers in the sperm of 13 lean men and 10 obese men, as well as the sperm of six obese men before and after weight-loss surgery, Live Science reports. According to the study, the sperm of lean men and obese men had very different epigenetic markers for genes related to brain development. Meanwhile, the sperm of obese men before and after surgery had major differences in epigenetic markers for genes related to appetite regulation.
The study provides "early evidence that sperm carries information about a man's health" and not just his genes, Live Science reports. The study's author, Romain Barres of the University of Copenhagen, says the results could mean men should change their behavior when trying to have children in the same way women change their behavior while pregnant. The results of the study seem to confirm earlier research by Barres, which found rats fed fatty food tended to have fatter offspring, according to the Times. But the new study doesn't actually show if the changes in epigenetic markers affected the participants' children, and experts have expressed concern over the study's small sample size. (A study of Holocaust survivors found they passed their stress onto their children through a similar process.)