The Minnesota experiment that was led by Ancel Keys, focused on how hunger and starvation affect humans.
It is pretty interesting and worth a read to fully understand why humans tend to gain back more weight when they diet excessively.
Many in the study reported eating excessively after they left Minnesota; Jasper Garner described it as a “year-long cavity” that needed to be filled.
No amount of food would suffice - even though they become physically sick.
The body memory of hunger was traumatic and the overcompensation in the time thereafter overrode any amount of self-discplinine whatsoever.
Basically, the conclusion is - do not starve yourself.
You will only get fatter - which is usually what most people are scared of in the first place, thus why they start obsessively restricting.
Dieting is not the solution though.
You can read the study here.