Excerpt from the book Im reading:
The weekly magazines simplistic weightloss advice has lead many on a bothersome stray, where starving periods replace over-eating. Of course the calories intake in the long run needs to go in minus, but its not where the best payout is. To reduce the energy-intake is just a little part of what is needed to reach the goal. If you have to reach it there are a couple of things that is needed: You have to eat correctly and until you are full, you need to exercise more, sleep better and reduce the negative stresslevels. Therefore weightloss diets, that only is about you eating less, are doomed to fail. Fact is that there are 5 times bigger chances that you will stop smoking than you losing weight on those methods........
...Evolution has ensured that the body is etremely good at handling the risk for hunger and malnutririon. Its what you can call hardcore physiology: The brain and the homones ensure in unification to save the calories: They make sugar out of anything they can get their hands on and first of all - ensures that the whole organism is on standby, so no energy is lost. Your brain signals to the cells that there is a crisis and the body goes on standby. "Starvation! Hunger! Bad times! Find food! Get something sweet!" Its not strange, that its hell to lose weight with conventional methods. In addition to that its cruel, since the calories get consumed at a lower rate and storage of fat in the body increases. Its quite smart f its about surviving a period of starvation - but really bad odds for the person that want to lose surplus kilos.
To cut down on calories and fat will in the long run give bad result than strategies that focus on the intake of carbohydrates (Shai et al, 2008). The main reason for this is behind your ears. Your mood deteriorates, when you are forced to live with an insulin-bonus, while you still dont get enough calories. And after some time all you can think of is food and eating. Your brain uses all its energy to find quick energy and sends you on a mission of calorie hunting (Kemmotsu & Murphy, 2006)
Because the body functions like any other machine, some of the energy disappears again in the form of heat. Not only are you hungry and depressed, you are also freezing. It is simply not fun to lose weight in this manner. Regardless, many known diets that focus strictly on how many calories you eat do not spend time on what food is good or useful. The diets are not only inefficient (Hession et al, 2009), the brain and body forces you to mistakes that gives feelings of guilt and failure. The outcome is that many on diets are not honest when asked how the diet is going (Lichtman et al., 1992)