I had thought, like scholars such as Vaclav Smil:
https://inference-review.com/article/good-eats that the present obesity crisis was due to an over-supply of carbohydrate-rich food. But then I stumbled across a reply to this by Edward Archer, and had a brief re-think:
“It should be obvious that a large food supply does not inevitably lead to obesity. After all, a large body of water does not inevitably cause drowning and an abundance of atmospheric air does not automatically lead to hyperventilation. Just as one individual drowns in a bathtub while another swims easily in an ocean, obesity is surging in nations with relatively small food supplies, such as Botswana and Nigeria. At the same time, many individuals in nations with a surfeit of food, such as Switzerland and Norway, remain lean and healthy. The size of the macro-environment—that is, the body of water, air supply, and food supply—is not relevant, nor even related to these outcomes. There is no valid relationship between a nation’s food supply and its levels of obesity and metabolic diseases. Compared to Switzerland, New Zealanders spend a greater percentage of household income on food and have a smaller per capita food supply. Nonetheless, New Zealanders have an obesity prevalence approximately 250% greater than the Swiss. From 1910 until the 1960s, the per capita food supply in the US decreased from 3,500 calories to 3,100. This reduction was accompanied by an increase in body mass. Both logic and empirical data refute the notion that a surfeit of food, whether as a result of lower costs or a larger supply, is a causal factor in obesity and metabolic dysfunction.