You could consider in the same way as the explanation for altruism - that families and communities who can rely on helpful old people to raise the children perform better and out-compete families/communities without that resource.
We should also consider that any dietary pressure will have only existed for at most a few thousands of years which, in evolutionary terms, 1000 generations perhaps, is basically nothing.
You’re speaking to modern times. Rebeccu, for instance, is a gorgeous town abandoned by Sardinians in the 14th century because of famine. Furthermore, the children of a famished mother are less likely to survive to reproductive age, and a family whose elderly died of famine will be less stable than one with multi-generational structures in place. These prenatal, neonatal and group selection dynamics bias the dice.
Bugs might reproduce primarily constrained by their LDL uptake but humans are far more complex.
This sounds like it would be fascinating in general.
If they want to reproduce, don't they have to search outside their tribe for a sperm/egg donor and possibly surrogate? So at least 50% or more of their reproductive health comes from outside the tribe?
Attempts to characterize behavior show homosexuals more commonly staying with parents and supporting relatives. The usual explanation for this is that they are not interested or able to compete in the usual mating and paring rituals. It isn't that they want to reproduce so much as they want to contribute to the tribe and in doing so result in the reproductive capacity of the entire tribe being increased.
Ireland https://www.theguardian.com/environment/2022/apr/22/northern... Netherlands https://www.theguardian.com/environment/2021/dec/15/netherla... Belgium https://www.brusselstimes.com/251313/government-advisors-pro...
No, this is not true.
More info: https://www.ncbi.nlm.nih.gov/books/NBK326741/
Additionally, ApoB is an excellent biomarker of cardiovascular health risk.
Might just be semantic quibbling, though.