It’s becoming apparent that men and women have much more influence on their future children’s health than has ever been considered before. Not only do the mistakes parents make when feeding children affect children's weight, but parents' own lifestyles and the environment they live in can actually change the genetic material their offspring inherit, setting them up for good health — or bad.

That weight loss in future fathers has the potential to affect the eating behavior — and weight — of their as yet unborn children is game-changing information.

When researchers compared sperm cells from lean and obese men, each was found to possess different epigenetic marks that could change the next generation’s appetite. In another finding, six men who were followed before and after gastric-bypass surgery had an average of 4,000 structural changes to their sperm cell DNA as a result of their weight fluctuations.

“We certainly need to further examine the meaning of these differences; yet, this is early evidence that sperm carries information about a man's weight. And our results imply that weight loss in fathers may influence the eating behaviour of their future children,” Romain Barrès, one of the University of Copenhagen researchers, said in a statement.

We know from epidemiological studies that nutritional stressors such as famine in one generation can adversely affect the health of offspring generations later. The current study identified the molecule in human gametes that could be responsible for this effect, according to Barrès, and found that the genetic information carried in a father’s sperm has the potential to affect the development of an embryo and go on to shape a child’s physiology.

The choices that young people make in terms of their health may go much further than just impacting their own lives. It could impact the lives of their children and grandchildren.

In the context of obesity, that weight loss in future fathers has the potential to affect the eating behavior — and weight — of their as yet unborn children is game-changing information.

“Today, we know that children born to obese fathers are predisposed to developing obesity later in life, regardless of their mother's weight. It's another critical piece of information that informs us about the very real need to look at the pre-conception health of fathers,” Ida Donkin, MD, one of the lead authors of the paper, added.

The importance of pre-conception lifestyle factors, such as diet and exercise, to the health and development of future children is a message that needs to be stressed to young people. Traits that were once thought to be simply inherited now could prove to be modifiable, and the choices that young people make in terms of their health may go much further than just impacting their own lives. It could impact the lives of their children and grandchildren.

The study is published in Cell Metabolism.