I came across this fantastic paper that looks at anorexia from an evolutionary perspective. The authors hypothesize that initial bouts of calorie restriction (aka dieting) set the stage for later anorexia.
From the full-text:
"The goal of the starvation response is to conserve energy, delay growth processes, preserve cellular levels of ATP (in part, by increasing the efficiency of energy metabolism) and minimize oxidative damage. This response is essential for survival during times of food/nutrient shortage and is, consequently, highly conserved through evolution."
"The net result of deficits in the starvation response is that patients fail to exhibit normal appetite or to properly regulate their response to fasting and fuel shortage. This leads to a vicious cycle. Thus, a bias toward denial of food leads to a reduction in calorie consumption, and weight loss. As weight loss proceeds, production of ancillary signals to initiate feeding, such as IGF-1 and dopamine (controlled by FOXO), is diminished and the starvation response is further activated. However, because this response is defective in AN (anorexia nervosa), counterregulatory (orexigenic) mechanisms are ineffectual, and a persistent catabolic state develops, much like anorexia associated with cancer or infectious diseases. The fact that some anorexic patients literally starve themselves to death attests to the failure ofevolutionarily conserved survival strategies in AN. "
"Efforts to treat AN solely with behavioral approaches may have had limited success because they target the sequelae of the disorder rather than the etiology, and rely on ‘will power’ when the real culprit may be a metabolic defect akin to the situation in diabetes mellitus."
They also mention Ancel Keys and his starvation experiment in the article as well.
Overall, they show that anorexia could be an evolutionary mechanism gone haywire, as is the case for other modern maladies.
The pdf is on the web if you search for it.