Chapter 20   Unconventional Diets 

For fifty years, JAMA disregarded firsthand testimony from clinicians and trivialized the scientific issues; it promoted diets not because they were effective, but because they were supposedly "least harmful" based on its own notion of harm. "Experts" trumped personal testimony and the experience of clinicians. 

Accepting that high-calorie diets can lead to greater weight loss than semi-starvation diets requires overturning certain common assumptions. One is that a calorie is a calorie, which is typically said to be all we need to know about the relationship between eating and weight. 

Carb restriction is similar to fasting. Since fat and protein are the energy sources in fasting, there should be little difference in cellular metabolism whether the fat and protein come from internal or external sources - and this turns out to be the case. The metabolic responses of the body are virtually identical. When we fast, the protein and fat come from our muscle and fat tissue; when we restrict carbohydrates, they're provided by the diet as well. 

Another paradox: 

Weight loss can be independent of calories

Hunger also can be independent of calories

In fasting, there is no hunger. Why is it when we add carbohydrates to the diet we get hungry, if not irritable, lethargic and depressed - but this does not happen when we only add protein and fat? 

Alfred Pennington metabolic fault can explain why and how malnutrition and obesity can coexist. The adipose tissue amasses fat calories in a normal manner after meals, but it doesn't release those calories fast enough to satisfy the needs of the cells between meals. This is the metabolic defect that causes obesity, he said, and could be corrected by removing carbohydrates from the diet. A low carbohydrate diet mobilizes body fat and this can be used for fuel.