Diets That Work Must Mobilize More Fat from the Fat Tissue Than Gets Deposited There
Diets that work have nothing to do with calorie control, according to the Lipophilia Hypothesis. This theory tells us instead that the fat "is working for itself." When we get fatter, we are driven to eat more and exercise less. To get thinner, we need diets that work to fix whatever made us fat in the first place; only then will our appetite and metabolism compensate.
If this sounds confusing -- like the tail wagging the dog -- go back and review the essay on the Lipophilia Hypothesis. Better yet, check out Gary Taubes' book, Good Calories, Bad Calories. Or watch this video. Or read this article.
Lipophilia tells us that eating less and exercising more won't help us lose weight. On page 300 of Good Calories, Bad Calories, Gary Taubes explains why diets that work must do so by addressing fat metabolism problems.
He says that overweight patients who go on calorie-reduced diets will always be struggling against two urges: 1) to eat more calories; and 2) to be less active. These impulses will inevitably win out, not because the patients lack willpower or mental toughness, but because their bodies ultimately give in. (The resting metabolic rate, for instance, can slow to compensate for the lack of calories in the diet and thus drive weight gain.)
The bigger point he makes is that this phenomenon -- the fat tissue striving to maintain itself in the face of calorie deficit -- clearly suggests that obesity is a physiological problem. Until you fix what Taubes calls "the underlying abnormality" in the body, the weight problem will not go away. You may be able to seemingly fix the problem in the short term, but this is akin to starving a child to keep him from growing.
To summarize: we have two vastly different predictions from two vastly different theories:
The Lipophilia Hypothesis says that eating less and exercising more won't lead to weight loss; whereas managing insulin levels will.
The Caloric Balance Hypothesis says that diets that work should revolve around calorie control; when we restrict "Calories In" and/or increase "Calories Out," we should lose weight -- eat less and exercise more, that's all there is to it.
Both theories make very testable predictions. Only one can be right.