I Don't Think So

The NY Times discusses the weight gain/loss issue and blames the brain rather than will power. They state:

The root of the problem is not willpower but neuroscience. Metabolic suppression is one of several powerful tools that the brain uses to keep the body within a certain weight range, called the set point. The range, which varies from person to person, is determined by genes and life experience. When dieters’ weight drops below it, they not only burn fewer calories but also produce more hunger-inducing hormones and find eating more rewarding.

No the root problem is that 3500 Kcal equals one pound. And if you only burn 1200 Kcal per day you have a problem if you consume 2400 Kcal per day, you gain 1 pound every 3 days! Now the problem is burn rate. Genetic control has allowed certain peoples to live on fewer calories. Native Americans in certain areas were living off of very few calories and when introduced to a European diet one saw massive levels of obesity and Type 2 Diabetes. When they had fewer calories they did well and survived, it was the diet change that did it.

The problem in my opinion is what we allow ourselves to consume as food. Often also it is the spouse or family that is non-supportive and almost antagonistic to the dieter. The environment during the weight loss period is focused but then after it returns to an excess caloric one where all too often family members reinforce the eating misalignment.

Thus it may very well be will power, but the will power of the family and friends to change.