A low protein diet (9% of total calories) caused changes in testicular epigenetics and males had offspring that were overweight with symptoms of type 2 diabetes and reduced activation of genes which regulate fat metabolism (mouse study).
The low protein diet changed the testicular expression of many folate-cycle enzymes (ie. Dhfr, Mthfr, and Mtr) and also changed DNA methyltransferases resulting in global hypomethylation.
This study was done in animals and further research is necessary to determine how much of this study’s findings can be translated to humans.