fatnutritionist:

Most diets seem to succeed in the short-term, and fail in the long-term. This is not a new, or even particularly controversial, observation among researchers…

The usual assumption among non-researchers about why diets fail is that when a dieter regains weight, it must be because they stopped dieting, which is in turn attributed to things like not having enough willpower, personal and moral failure, gluttony and laziness, or being too ignorant to know better.

These are assumptions which reflect the mythology of our culture: that anyone, if they try hard enough, can be anything they want — and therefore that weight is entirely a choice, a product of effort and moral character. This story centres the individual, their behaviour, their character traits, and their moral attributes as the cause of fatness in the first place, and the reason why weight is regained following a diet.

But these explanations are not satisfactory to me, nor, as you will see, are they reflected in the scientific literature.