Remember the "simple physics?" As in, more calories in than calories out means weight gain? And more calories out than calories in means weight loss? That's all there is to it, right?
Except....practically everyone here talking about how they lost weight is also talking about their exercise regimen. Well, the simple physics also shows that exercise has nothing to do with weight loss. Exercise simply does not burn up enough calories. Maybe exercise keeps away from the dinner table, but in my skinny days, my only exercise was in a bar and the sack, never a gym. My anecdote trumps yours, because it was a hell of a lot more fun!
Seriously, though, the stunningly obvious self-contradiction in the arguments presented conclusively show that deep-seated notions about body image, sexual desirability, the plasticity of the self, the power of the will, hell the freedom of the will, and many more are still at work, despite the supposed recent availability of scientific literature.
For a little perspective, remember there was a vast and varied literature about the causes of ulcers, much focused on personality traits rather than heliobacter pylori. Similarly, hypertension is attributed to temperament (or just plain temper.) Anxiety is attributed to cowardice or neurosis rather than cardiac rhythm. Stress as a cause of disease still is overlooked, probably because the conclusion that modern (capitalist) society is stressful is unwelcome news for apologists.
Again, it just seems wiser, as well as more humane, to quit making easy assumptions about personal inferiority.