Humans do not adapt to changing conditions, humans alter their immediate surroundings as desired—or migrate to eat someone else’s porridge.
Short term, and when those alternatives are available, that is usually true. However, Eskimos (Inuit) have been found to have genetic mutations that allow them to process their high fat diet differently (more "positively") than, say, white Europeans.
It's fascinating stuff: https://www.sciencedaily.com/releases/2015/09/150917160034.htm