See it's really fascinating, because actually there's a lot of scientific evidence that shows that it's NOT as simple as "weight change = calories in vs. calories out". That is why most diet regimes fail - we are constantly told that to lose weight, we need to decrease caloric intake and increase exercise, in order to create a 'negative energy balance.' But apparently, your body just doesn't work like that. That is a reason why there are many people who eat actaully very little calories but are still very overweight, or why obesity and malnutrition often coexist in the same populations.

First of all, caloric intake is dictated by the energy needs of your body. Obese people's appetites are not 'uncontrolled,' they are regulated. It's a common belief that overweight people simply lack self-control, that hunger is a feeling in your head and you need will-power. but "hunger and satiety are manifestations of metabolic needs and physiological conditions at the cellular level, driven by the body" (p. 433). so, when you go on a low-caloric diet, your metabolism and energy expenditure decrease. This makes sense for skinny people, who do not have a big energy supply. But for obese individuals, the same phenomenon will occur, as if they are starving too. Both lean and obese people become hungry and lethargic for identical reasons - their tissues are not receiving enough nutriment. this is also why it is hard to exercise in order to create negative caloric balance - at the cellular level, your cells are undernourished and lacking energy.

obesity seems to be caused by an imbalance in the hormonal regulation of adipose tissue and fat metabolsim. there is a cycle of storing fat and releasing fat, and the main driver is insulin, which promotes lipogenesis (fat synthesis and storage) and consequently hunger (by removing the available fuel (free fatty acids) from the bloodstream). This is why insulin is secreted in the morning upon waking as well as after eating (to store energy), and then ebbed away after the last meal (so you can sleep without hunger). For many people, insulin levels remain elevated for longer than normal (pre-diabetic.. too much carbs..) - this causes us to "fail to balance the inevitable fat deposition with sufficient fat oxidation. Our periods of satiety are shortened, and we are driven to eat more often than we should...As long as insulin levels remain elevated and the fat cells remain sensitive to the insulin, the use of fat for fuel is suppressed."

In addition, there is a study (maybe more? there are a billion in this book) in which ppl ate 1000 calories of mostly protein/fat and felt sated, while ppl who ate 1000 calories of high-carb, low-fat foods were ravenously  hungry. And then interestingly enough, they then tested a diet of 1000 calories of mostly protein/fat PLUS 400 additional calories of carbs. And guess what... these people felt HUNGRY! even though they were eating MORE calories.. also, insulin therapy was used to treat anorexics back then, as it would make them immediately hungry. Interestingly, though it didn't work to cure schizophrenia in patients (they used it on sylvia plath and john nash), it did cause them to gain weight.. so clearly, the type of calorie matters. Your body isn't that simple of a machine!

there's also research that with hyperinsulinia, cells become desensitized but not at the same rates. Fat cells stay sensitive the longest. Thus, when the body is secreting more and more insulin, this has a much more profound effect on the fat cells. also, cancerous cells tend to have many more insulin receptors than normal body cells.

Also, with regards to the saturated fat stuff. it's true, there is no research that shows more saturated fats increase chance of heart disease. CRAZY, right? the American heart association and everybody keeps stating this, but there's no evidence! in fact, there's a lot of contradicting research that shows the opposite! Yes, i was shocked by this too. We always hear about how Americans eat more saturated fat now than ever. That's false. Americans ate lots more meat before, and we're not talking about 98% lean meat!  we have actually decreased our fat intake, and instead eat much more carbs than ever. We always hear about how Japanese people eat very little fat, then come to  America and get our 'western/chronic' diseases. They also eat much less calories in general, as well as less carbs than us! What we hear is always very selective and biased. There are tons of cultures that eat tons of meat, and have almost zero occurrences of heart disease, diabetes, obesity, cancer, ulcers, etc. These are cultures like the Inuit Indians (99% meat, and no, they never got scurvy or osteoporosis or anything!), Masai, Samburu nomads, Australian Aborigines, Native Americans of the Great Plains... when they became westernized, they didn't eat MORE saturated fat or cholesterol... they actually decreased those foods, and ate more carbs..

Seriosuly, look through this book. It is just astounding. As a researcher (not health.. I do physics/applied mathematics, lol) it was really enlightening because you see the crazy politics behind some of our health policies and guidelines. It's not as if this research was done by quacks or by less-reputable scientists, or that there was very little research on these topics. No, there's a crapload of research contradicting many of our health guidelines, it's just that some old hypothesis's have become dogma and ingrained in us and in our government officials and even scientists who are unconsciously biased because of what they themselves learned in med school and such.. it's all just become a self-perpetuating falsehood, and americans, because of these so-called health guidelines, aren't becoming healthier.. they are becoming sicker, and if not physically, than mentally with the stress of trying to stay healthy in impossible ways (who seriously can run a few miles and NOT eat more to compensate?)..

it also cites all these articles by the NY Times that totally skewed research results or outright ignored them. It shows how the media has its own interests to preserve.. I always read the NYTimes Health section and totally trusted it, but now.. no way... Especially since they come out with their own diet books and stuff, of course they don't want people to think it's false! It is just incredible what is being told to common people, and what is known among scientists but never publicized. and also the lies that are created (no im not an atkins dieter, obviously, but i hate it when people say that dr. atkins was obese or that he died of heart disease, or that he was a quack researcher/doctor, etc.. especially at his death too... and especially when other doctors were saying this and calling low-carb diets dangerous and such, without any such proof but just because of the dogma). Diet and nutrition have become so political and so.. personal... but i think we need to look at the facts, and not be afraid of them..

wow that was long, sorry!