As a follow up on the descendant study from China, your link shows that children with a mother that experienced childhood famine have an average BMI that is higher by ~1. Children with fathers who experienced childhood famine actually have a lower BMI. This study doesn't control for the obvious cultural and behavioral implications of a parent living through the famines, although epigenetic connections have been proposed elsewhere [0]
Here [1] is another study from China That shows that simply having an obese parent is the single biggest factor in a developing childhood obesity, and nearly doubles the obesity risk.
I didnt bother digging up a study, but this link[2] says that in the USA, a child with 1 obese parent has a 50% chance of being obese (absolute, not increased hazard ratio!) If both parents are obese, a child has an 80% chance of being obese!
This makes a lot of intuitive sense to me. I would expect the modeled behavior, status, household food, and parenting to have a huge impact on children. This naturally overshadows the interesting but tiny impact of epigenetic transmission.
I was expecting you to link the transgenerational study from polish famines during world war II, so thanks for some references I haven't seen before. That said, you have to admit that they are a hell of a lot of variables at play when you're talking about populations that self-reported food insecurity or underwent literal famine.
That said, if you are worried about the next generation, it'd be interesting to compare the magnitude of transgenerational effect from simply being raised in a household with obese parents in the usa. I imagine it's much larger but I'm not on a pc to look it up right now.
Last, if I were to lazily steel Man my appeal to nature, I doubt our Neolithic ancestors yo-yo'd back and forth between skinny and obese generations due to calorie restrictions.
Also increases CVD and mortality [1]. And causes your descendants to be fat [2].
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC7792411/
[2] https://pubmed.ncbi.nlm.nih.gov/36507560/