hunter gatherer clue to obesity.

[Timelord]

Peoplw who are skinny now would be clinically anorexic on a hunter gatherer diet.

People who are heavily built, verging on overweight now would most likely be in good shape on a hunter gatherer diet.

people who are overweight/big now on a modern diet, would probably be a well built, solid proposition.

Take away the modern diet with all its additives etc and the majorities sedentary lifestyle, then the metabolic rate of individuals, combined with calorie intake & daily exercise, would result in a very different picture of apparent health. Those skinny fast metabolic folks now, would be undernourished and weaker as a result.

Having some fat reserves, whilst being cardio fit gives the highest mean long term survival prospect weighed against negative issues of diet & temperature. Of course that is just average statistics and not correct for each individual scenario.