My argument is that the calories in (eaten) &#x2F; calories out (exercise) explanation, and <i>the idea it is just that simple and if you&#x27;re not losing weight you&#x27;re cheating on your diet or lying about your exercise</i> is wrong.<p>You seem comfortable with the idea that different individuals have differences in caloric uptake (Suppose I extract 1500 calories from a meal, and you 1800 calories from the same meal), but I don&#x27;t think others are comfortable with that idea.  And if it varies across individuals, why is it <i>impossible</i> to vary with one individual over time, or change drastically in a short period of time?  Can the physiology of your body change to (for example) start extracting more calories from food than it normally does?  It doesn&#x27;t seem like that crazy of an idea to me, and if it can do this (as anecdotal evidence suggests), then it makes weight loss strategies much more complicated, and it makes the simple calculations no longer work under all scenarios.<p>This doesn&#x27;t seem like a terribly controversial idea to me.