> It took me several decades too long to understand the obvious, that exercise is for building strength, and losing weight happens by eating less.

Exercise does much more, and does have some impact on weight, according to the next paragraphs of the article:

But Thyfault warns that message may do more harm than good. People who exercise are less likely to gain weight in the first place, and those who exercise while they diet tend to keep weight off better, he says. Exercise also can impact where fat is stored on the body and the risk of diabetes and heart disease, he says.

Pontzer agrees that exercise is essential for good health: The Hadza, who are active and fit into their 70s and 80s, don’t get diabetes and heart disease. And, he adds, “If exercise is tamping down the stress response, that compensation is a good thing.” But he says it’s not fair to mislead dieters: “Exercise prevents you from getting sick, but diet is your best tool for weight management.”