Anorexia nervosa is a life-threatening disorder that humans arguably brought upon themselves, but so little is known about this condition that it may be very difficult to reverse the effects and eliminate causes. An extreme concern about being overweight leads to the disorder’s leading characteristics of diet and excessive exercise. It is 10-20 times more common in females (especially young women) and is considered a mental disorder developed through heredity and / or societal pressure. However, this latter notion is the major flaw because there may be more to the problem than simply a voluntary desire to become deathly thin.
Take the famous 1946 Minnesota Semi-Starvation Experiment for example. The study modified the caloric intake of healthy men while observing the psychological and physical effects over a 60-week period. The first 12 weeks were a control period, in which each individual consumed 3200 calories per day in order to reach his supposedly ideal weight. The following 24 weeks consisted of the semi-starvation “diet.” The prescribed caloric intake was determined by the man’s ideal weight. Researchers aimed to bring each subject to 75% of his normal weight with two meals per day. For 12 weeks afterwards, each individual was administered a strict rehabilitation diet to re-nourish him back to health. In the final 8 weeks, caloric intake was unregulated but monitored.
In the physical context, we would expect the subjects to become tired due to the lack of nourishment. Their body temperature and breathing and heart rates would naturally be reduced because of the fewer nutrients. However, these semi-starved men displayed anorexia symptoms as well! Many subjects demonstrated psychological distress and depression. They developed rituals and obsessions over eating yet could not explain their actions.
Evidently, semi-starved individuals exhibit symptoms of anorexia, but more importantly, this finding proves that anorexics may be influenced at the neurochemical level (because starvation causes alterations in neurotransmitter secretion and hormonal balance).
Studies on anorexia show that, in the brain, levels of the neuropeptide Y (NPY) increase. This neurotransmitter is found among the neurons of the arcuate nucleus, which is located at the base of the hypothalamus. Normally, increased levels of NPY induce insulin secretion, lower the body temperature, and maintain the fat storage of triglyceride within cells. Most significantly, NPY increases appetite and consumption. But during starvation, higher quantities of NPY reportedly lead to increased physical activity. Thus, when seeing food, a semi-starved individual may actually feel less inclined to eat and more inclined to exercise. This trait is very similar to the exercise and diet preferences found in anorexics.
At the endocrinological level, studies* show that the joint effect of various hormones aids anorexia’s symptoms as well. Anorexics normally have lower levels of leptin, a hormone that increases metabolic activity and reduces food intake and NPY secretion. With less leptin, the metabolism is slower and increased NPY secretion discourages eating. In addition, patients’ insulin levels rise when they smell food. This activity is counterproductive because more insulin promotes the satiety sensation.
Altogether, along with starvation, prenatal and hereditary factors can also contribute to the onset of anorexia.
So far, I have not described any gender-discriminating causes behind anorexia. Society prefers thin women, but is this mindset substantial enough to make the disorder so much more common among females? A 2006 study on female and male high schoolers proves otherwise.
In the experiment, students attended a free buffet lunch in which each student’s total consumption was monitored. A week later, they returned to the free buffet for lunch. This time, however, they had not eaten since the previous midday’s meal. Surprisingly, the consumption results differed between the genders. The males ate more food at a faster rate when they were under starvation. This was expected because the boys were naturally hungry after a day of starvation. But the females, in converse, ate less food at a slower rate than they had done in the previous buffet.
This high school study’s conclusion implies that food-reduction diets affect females and males differently. Thus, a female’s diet meant to lose weight may cause physical or endocrinological changes that actually produce anorexia.
Because various degrees of anorexia have prevailed throughout centuries, it is important to fully comprehend the causes and effects. Misunderstanding such an influential disorder has created an unalterable mindset toward specific individuals in society. Future studies will hopefully unveil more certainties that will transform the perspectives of anorexic individuals and their communities in the process.