There do exist some arguments for this, eg overweight parents with overweight kids, but obviously there isn’t some kind of ‘working class gene’ even though children are reasonably likely to have the same social class as their parents, and wealthier countries may have, on average, taller citizens even though height is strongly heritable. But one would certainly still expect genetic variation in eg thyroid function or whatever.
A few simple observations which don’t support the relevance of this genetic determinism argument:
- a few hundred years ago very few people were overweight. But maybe many people lived their lives incredibly hungry the whole time.
- wealthy countries where getting sufficient food is not the issue have variation in population-level statistics for obesity. Even if one claims that these countries are on-average different genetically in some ways (unlikely in the sense that genetic variation between large classes tends to be smaller than the variation within), one would expect America to mostly be a mix of old-world statistics whereas they come out exceptionally instead.
It seems to me that cultural expectations around food and weight will have a big difference and variation between countries, and that the kinds of food available and commonly consumed (eg sugary drinks, unhealthy fast food, etc) may be a big influence.
But none of this would mean that a particular individual is or is not overweight because of genetic factors rather than their environment.
A few simple observations which don’t support the relevance of this genetic determinism argument:
- a few hundred years ago very few people were overweight. But maybe many people lived their lives incredibly hungry the whole time.
- wealthy countries where getting sufficient food is not the issue have variation in population-level statistics for obesity. Even if one claims that these countries are on-average different genetically in some ways (unlikely in the sense that genetic variation between large classes tends to be smaller than the variation within), one would expect America to mostly be a mix of old-world statistics whereas they come out exceptionally instead.
It seems to me that cultural expectations around food and weight will have a big difference and variation between countries, and that the kinds of food available and commonly consumed (eg sugary drinks, unhealthy fast food, etc) may be a big influence.
But none of this would mean that a particular individual is or is not overweight because of genetic factors rather than their environment.