When all the food was produced 'naturally' more than 30% of the population worked on farms. Most people are fat, today, because they eat prepackaged foods, don't get enough exercise. If they work, their jobs are extremely sedentary. I could go on. In addition, prior to the proliferation factory canned foods, at least 50000 people died each year from salmonella poisoning due to home canned products not being sanitary.
A hundred years ago, obesity was basically unheard of, even among the sedentary. There’s an image of people getting off a barge in 1910 NY, and there’s not a single fat person to be seen, even among your white collar workers.
In fact, the obsession with exercise is something new...
It’s the food, salmonella aside.