Epigenetics is the study of changes in organisms caused by modification of gene expression. If these articles are to be believed, then these tRNA fragments positively influence the expression of regulatory factors. It seems like an example of epigenetics to me.
> It seems like they are trying to sell a classical misconception.
I don't disagree with this assessment. The study I cited¹ said something about tRNA fragments being a conserved response to oxidative stress. The news article apparently takes this and somehow turns it into a "your children will feel the consequences of your bad dietary habits" argument.
There is some discussion and references about diets and epigenetics in the scientific text but that's not what the article is about. The articles say (1) the epididymis sends some RNA to the sperm cells, and (2) that the lack of this RNA can compromise embryo viability. It's interesting and all, but the clinical relevance of this information has yet to be determined: I'm not aware of any evidence that supports the notion that bad lifestyle habits will affect this sperm maturation process in any way.
¹ https://www.ncbi.nlm.nih.gov/pubmed/21976287
> Accumulation of RNAs of 30–35 nucleotides that correspond to tRNA halves were first reported in Tetrahymena thermophila, and subsequently shown to be a conserved response to oxidative stress in a wide variety of eukaryotes.²