ELI5: Why do older people eat less and less as time goes on?

I?m housesitting with an eighty-year-old present and, prior to leaving, her daughter scolded her for not eating enough. It made me think of all the other elders in my life who also can?t or won?t eat much. I understand that digestion issues come with age, but even foods they are given the green light for seem to just be picked at and not enjoyed. What is the science behind that? Is that my future? I love food.


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