Psychology isn't all about emotions or psychoses. There are aspects of it that have nothing to do with sadness, gladness, or distorted versions of reality. The current model of dealing with psychological problems is largely pharmacological, so it focuses excessively on seeing problems as something that can be solved with the right pill that can balance the chemicals in your body. Those chemical changes, in theory, should push your body's biological balance such that you are more likely to do, feel, and think the way that society (and you) think would be best.
One of the things which is increasingly being left behind in the rush to see the body as a biological machine is that psychology isn't shaped entirely by chemicals, and not every problem can be solved with a medical procedure or prescription. Of course, we like to believe that is so because it is a lot easier to go under the knife, get an injection, or take a pill then to do other types of behavioral change. I'm no stranger to wanting an easy answer. Frankly, there have been many occasions on which I wish science would simply invent a pill that'd kill my appetite or make me understand a foreign language without having to study it.
That being said, I think that one of the reasons we are so bad at food management in our lives is that we aren't pursuing the right potential solutions for our particular problems. Yes, people eat for emotional reasons. Yes, people are driven by biological forces to have difficulty losing weight. However, understanding and dealing with these issues is only a part of the process. I can understand that I eat when stressed, when bored, or because it is my habit and I feel anxiety when I have to change my habits, but that doesn't necessary fix the problem.
I have come to believe that the next stage after understanding, is conditioning behavior. In old-fashioned terms, this would be learning discipline or moderation. I have talked before about learning moderation, and I think it's something that Americans in particular are poor at it. We live in a culture which encourages indulgence and glorifies those who live lives of ostentatious excess. We mock those who practice sensible habits and sound lifestyles as being boring or joyless. One of the reasons many dieters go to extremes is that being "perfect" and being a person of pure virtue is an extreme.
I think that "the other side" of psychology is fading into the background, because people who are adults in particular are poor at conditioning their own behavior. They aren't necessarily all that great at doing so with their children either, as is evidenced by the British T.V. show "Supernanny". Real behavioral change, whether it applies to yourself or to those in your charge, requires constancy. If you've ever seen "Supernanny", you'll see how the titular star's actions start to turn things around and then the parents' inability to consistently apply the same techniques cause things to fall apart.
Conditioning adult behavior, and in particular conditioning your own behavior is quite an order of magnitude harder. Part of the problem is that being your own therapist (like being your own doctor or lawyer) is not very effective. None of us can see ourselves as we really are, nor can those around us. There are too many vested interests to get an accurate picture of ones own problems and needs. Generally speaking, the only effective way to understand your problems deeply is to get outside opinions, and unfortunately most therapists these days are more than likely to give you a bottle of pills then a prescription for behavioral changes.
That doesn't mean there is no hope. I think that successful long-term weight management can be acquired through a mixture of disciplines and considerations. First, you have to understand yourself mentally and your body. Then, you have to deal with any medical issues. Finally, you have to deal with conditioning your behavior.
The most critical manner in which I can put this is that we have to learn discipline. In no way do I mean to imply that fat people lack discipline. That being said, I think that we're fooling ourselves if we believe we are capable of exercising sufficient discipline to manage a healthy weight for our particular bodies. Someone else may be able to exercise far less discipline and not gain weight, but that is actually irrelevant to our choices. It may not be fair, but some of us have to work harder than others and apply greater discipline than they do to gain the same effect. This isn't uncommon in many areas of life but it is trickier when it comes to food.
Sometimes I wonder if one of the many reasons that we have more overweight people in the world today is that we emphasize discipline less now than at any other time in our cultural history. In a highly individualized culture in particular, discipline is often scoffed at and actively rebelled against. We cram for tests instead of studying gradually as we go. We join health clubs as part of New Year's resolutions and then stop attending by the end of May. We know we should regularly clean the toilet but let it go until it gets bad enough to notice. We don't prepare for dinner and end up eating whatever is fastest and easiest rather than what is healthy and nutritious.
I'm not holding myself up as a paragon of discipline. I'm not. However, I do feel that part of the key to maintaining my losses and (likely) future healthy weight will be rooted in discipline and conditioning. Once I get through all of the psychological crap that got me fat and helped keep me there, it's the discipline that will move me from a state of understanding why I overate to actually stopping me from overeating. I think that we're fooling ourselves if we think understanding the psychology or even the biology of our weight issues will magically make the desire to overeat disappear just as much as we'd be fooling ourselves to think that discipline alone without psychological understanding is enough to keep us at a healthy weight in the long run.