I've just finished a quick read of "Turn off the Hunger Switch" by Paul Rivas, M.D. It included a lot of new studies and information for this traditional nutritionist. To summarize the book for you, Paul Rivas is a Bariatric M.D. thus dealing with clients who are overweight or obese. He contents that many of these people are overweight, not because they lack willpower or because they haven't made a good many attempts to lose the weight, but because of a chemical imbalance in the brain.
Appetite and weight control begin in the hypothalamus. One part of the hypothalamus, the ventromedial region, is in charge of telling you when you've had enough to eat, or that you're full. If this part is damaged, enormous hunger and obesity always result. The feeling of hunger comes from another part of the hypothalamus, the lateral hypothalamus. If this part is damaged, loss of appetite and extreme thinness result.
Studies have shown that many overweight people do not necessarily eat more food, but they think about it a lot more, eventually leading to overindulgence or binge eating. Paul Rivas argues that these people have an underlying biochemical abnormality much like those with OCD or depression. By increasing brain levels of certain substances, like serotonin, that act as triggers for the hypothalamus, one can suppress appetite and overeating and also liberate people from obsessing over food.
Traditionally I would say that all people can lose weight and be healthy by diet and exercise, however, there do seems to be people, and studies to prove it, that respond poorly if at all to these traditional practices. Better said, if a person is dieting and exercising they may lose weight, but if they feel they are putting in a huge amount of effort for small results or starving themselves to lose a pound, these medical recommendations seem to make more sense.
Although I have personally experienced a wild appetite and bouts of depression, to the point where I felt out of control, I was able to pull myself from these symptoms over time, with much spiritual effort and without medication. However, these experiences lead me to better understand why people do seek out medical attention as these types of problems seem to be almost insurmountable by oneself.
Finally, I would always recommend diet and exercise as the primary means of losing weight and living healthy to all people. However, for those who feel completely at a dead end, hopeless and who absolutely NEED to lose weight for other health complications, I would suggest reading this book and making an appointment with a bariatric doctor.