I find their dismissal of calories-in/calories-out pretty unconvincing: > Pew says calorie intake in the US increased from 2,025 calories per day in 1970 to ab

I find their dismissal of calories-in/calories-out pretty unconvincing: > Pew says calorie intake in the US increased from 2,025 calories per day in 1970 to about 2,481 calories per day in 2010 [45]. The USDA Economic Research Service estimates that calorie intake in the US increased from 2,016 calories per day in 1970 to about 2,390 calories per day in 2014 [46]. Neither of these are jaw-dropping increases. > If we go back further, the story actually becomes even more interesting. Based on estimates from nutrient availability data, Americans actually ate more calories in 1909 than they did in 1960. A 25% increase in energy intake for the same biology is not jaw-dropping? Maybe not, but it seems like a lot to me, and a plausible explanation on its face. I need a lot more convincing that this is not the answer right here. Going back to 1909 for evidence of higher energy intake is not convincing either, most people at that time did hard physical labor every day - on a farm or in a factory.