I've never read the book, but it does seem to make sense that not all of us have the same metabolic needs. I mean look on this board, some people do beautifully on low carb, some people do not. My sister eats carbs carbs carbs all day, whatever she wants whenever she wants. Not complex fiberous carbs with protein, either, she eats sugars and white breads. Even though she eats this way, she never had the problems with crazy blood sugars and extreme hunger that sent me into a spiral of hunger and obesity.

On the other hand, my sister thinks the way I eat is absolutely disgusting. She hates the taste of "savory", heavy, protein food. She likes to graze on light carby type things. She doesn't have a problem with weight or energy.