https://en.wikipedia.org/wiki/Epigenetics_of_Human_Developme... https://sciencing.com/epigenetics-definition-how-it-works-ex...
>Other studies have looked at the effect of famine. When mothers were exposed to famine during pregnancy, as was the case in Holland in 1944 and 1945, their children had a higher incidence of obesity and coronary disease compared to mothers not exposed to famine. The higher risks were traced to reduced DNA methylation of a gene producing an insulin-like growth factor. Such epigenetic effects can be inherited over several generations. >Exposure of parents to cocaine may affect memory.
I can't find evidence of it, but it seems reasonable to extrapolate that long term life style choices will also affect epigenetics for the better.
There is growing scientific evidence in human and animal studies that should inspire every father-to-be to start exercising more and eating healthier before conceiving a baby. A wide range of studies have found that fathers who are obese at the time of conception pass on a predisposition to their children and grandchildren to be overweight, to develop diabetes, or both.
https://www.psychologytoday.com/us/blog/the-athletes-way/201...
Even if true that their children had higher rates of obesity this could easily be due to nurture - e.g. those Mothers could've been more likely to stock up on food at home and feed their children more due to the trauma, with the methylation explanation being post-hoc.
[1] https://science.howstuffworks.com/life/genetic/genes-turned-...