And your snark of "if you don't get it" is absolutely uncalled for here on HN. It's not appropriate.
What is not proven? That people gain weight when they consume more calories than they burn? That hunter/gatherers burn more calories than people sitting at a desk most of the day? That extra nutrient absorption might help active people?
https://journals.plos.org/plosone/article?id=10.1371/journal...
“average daily energy expenditure of traditional Hadza foragers was no different than that of Westerners after controlling for body size”
What is not proven? That people gain weight when they consume more calories than they burn? That hunter/gatherers burn more calories than people sitting at a desk most of the day? That extra nutrient absorption might help active people?