This research suggests that the lifestyles of men are written into their sperm and produce heritable traits that can be passed on to their children. Lean and obese men were found to be passing on different epigenetic information, particularly at gene regions connected to the control of appetite. This might explain why obese men often have obese children.

When the men lost weight as a result of gastric band surgery they found an average of 5,000 structural changes to the sperm cell DNA, indicating that positive lifestyle changes might improve the genetic inheritance passed on through the sperm. This is just one example of how a man’s lifestyle may positively or negatively affect the health and wellbeing of his offspring.

http://www.eurekalert.org/pub_releases/2015-12/cp-sci112515.php