I think he's just reframing the levels of causation a bit. You don't say pregnant women gain weight because they eat more than they consume, although from a the

I think he's just reframing the levels of causation a bit. You don't say pregnant women gain weight because they eat more than they consume, although from a thermodynamic point of view this is strictly true. Have you ever met skinny unhealthy programmers who are very sedentary and eat a lot of junk food? I have met many. The point is that different people have very different reactions to food, in terms of hunger, mental reward pathways, tendency to burn off calories through adjusting subjective energy levels (e.g. lethargy) and things like jittering, and hormonal responses. Some of this is affected by the kinds of foods we eat, and much of it is affected by genetics. The real point is that we can do better than saying "just eat less and exercise more" by looking at things from a different perspective. (I'm speaking as someone who lost 45 pounds in the last year and am currently at about 10-11% bodyfat by the way.)