As most know, obesity is more than just being overweight. Besides the physical health risks assigned to obesity, the mental aspects of the condition are a major concern and in my opinion is the underlying reason not only for the weight gain, but also other symptoms that the person can identify with.
As an animal, humans don't have a genetic propensity to excessive weight gain. Unlike some other species of mammal that use fat as a a layer of insulation such as whales, or as a storage mechanism for lean winters such as sea lions or bears, humans don't have a semi-seasonal clock which can help to regulate the metabolism in times of low energy availability, nor do they have the skeletal structural mechanisms to deal with excessive weight gain (I.E. 4 legs to balance additional weight, or water to mitigate stress on joints). So being obese for a human is far more of a problem than it is for other animals.
These are the well-recognized, physical problems that can come from obesity. What about the mental aspects of obesity? In both the mental ramifications of being obese, and the causality for the obesity; I am a firm believer that almost all obesity, and weight related maladies that have not been identified by a specific physical medical cause (such as hypothyroidism or metabolic syndrome), can be tied back, at least partially, to psychological foundations.
When tackling the psychological aspects of obesity, we first must identify the trigger that causes someone to eat. Many times food is associated with comfort, security, safety, and happiness for the obese individual. Other times control issues manifest in the obese individual to gain weight. Psychological trauma from earlier in life can be a precursor to weight gain later. Often times, people with obesity issues use food as a control mechanism. when faced with triggers such as a stressful family environment, they turn to eating because they feel like their body is the one thing they have absolute control over, and eating is a natural way to react because food in most people's mind is associated with comfort and happiness. Some people cut themselves, others turn to drugs, and some turn to alcohol; food is fast becoming the method of choice for people who have unresolved psychological trauma.
Not all obesity is so obscured though. Sometimes the psychological issues induce stress, and stress releases a certain set of hormones in the body, chief among them is cortisol, a hormone released by the adrenal gland during high stress periods in order to increase vasodilation (meaning it widens blood vessel for higher blood flow) and increase oxygen delivery. Unfortunately, cortisol also inhibits insulin sensitivity, which means more blood sugar in the body, and a higher rate of body fat storage. During times of exercise related stress, cortisol is a good thing; it allows the body to focus on burning fuel, and burn it faster allowing increases in strength and speed accordingly. This quickly dissipates the cortisol without much in the way of follow-on problems; but when stress comes from non-physical means, or there is no accompanying high intensity physical activity with the cortisol uptick, that's when this condition becomes a net detriment to the body. When stress levels are consistently high for long periods, people develop areas of fat, even if they don't significantly over eat.
So we have two distinct causalities for obesity, one is a means to mitigate psychological trauma; another is a biochemical response to high stress periods over long timelines. Both are obviously psychological causalities, and both require different treatments.
I feel that in both cases, cognition of the underlying causes is vital to resolution. I.E. a person can do all the extreme diets in the world, or receive weight loss surgery, or take pills; these are resolving symptoms of the root cause, but they aren't addressing the main problems, and thus, these treatments will only work in the short term. These types of extreme resolutions only feed the overall issues that people associate with the obesity. When they inevitably fail to keep the weight off, it adds to their feelings of failure and inadequacy, thus allowing for more potential of weight gain. Gradually becoming a vicious cycle of weight loss, weight gain, more weight gain, depression, and resolve and starting over again. Unfortunately, eventually this takes its toll on the body and weight loss becomes more difficult, and as the person’s physical ability to lose weight lessens, so does their mental strength to fight the obesity.
I make no case to solve obesity in any one specific way, as each person requires slightly different techniques to solve their issues (thus no one diet or pill will ever cure obesity), I will say that stress reduction techniques, and mental health counseling are a big part of any plan.