The underlying assumptions are "all else equal". There are many dietary philosophies that structure what is allowed via subjective explanations of controlling

The underlying assumptions are "all else equal". There are many dietary philosophies that structure what is allowed via subjective explanations of controlling cravings, etc. IOW, food choice affects selection, invalidating "all else equal". Carbs may cause obeisity/wg more per calorie than fiber, but it's important to keep in mind a "dose response" concept.