The whole point of the article is that the traditional &quot;calories in&#x2F;calories out&quot; model is wrong.<p><i>&quot;Based on the research, Pontzer has proposed a new model that upends the the old &quot;calories in, calories out&quot; approach to exercise... He calls this the &quot;constrained model&quot; of energy expenditure, which shows that the effect of more physical activity on the human body is not linear.&quot;</i>