"Why We Get Fat" by Gary Taubes is an absolute landmark of a book.
He has the right mix of observations designed to get the mind going and prime a search space for evidence, and citing hard proven science, and comparing different points of view, and looking skeptical at conclusions accepted with poor evidence.
I don't know if his hypothesis is true about fat cells taking priority over nutrition in some cases (high carbohydrate diets and insulin resistance primarily) -- but if it is, it's a total game-changer. Obesity becomes, thus, less about willpower and character, and far more about people being nutrient-depleted and in a terrible state of mind and body despite eating over the caloric needs.
It's fascinating. It's amazing. It's exactly what a popular science book should be. It's more from the perspective of public health and science-in-general than a tactical manual -- there's not much in the way of tactics in it -- but it did change how I think about the brain, body, and hormones.
I feel a lot more sympathetic to overweight people. Much moreso. And it got some discussion kicked off in my head about various insulin sensitivity levels and diet tolerance different people have, genetics mixing with environment, etc.