Bulimia is often a side effect of anorexia for two main reasons. First of all, we as humans are programmed to survive and food is the software that makes this possible. Therefore, many anorexics are simply unable to sustain starvation and so motivated by signals from the brain that tells them they need to eat, they will consume thousands of calories in a bulimic rage and then purge it through destructive means such as self-induced vomiting. Secondly, the personality factors that distinguish restricters from bingers such as impulsivity and chaotic family situations come into play. Although they may start out restricting, those who fit this profile often eventually engage in bulimic behaviors as well.
Personality changes because improper nutrition causes actual changes in one s brain chemistry.
Apathy, anger, nervousness, depression and anxiety are all common reactions to starvation. As well, people tend to become isolated, withdrawn and experience drastic reductions in sexual desire. The ability to concentrate, comprehend and use good judgment is severely impaired. Severe fatigue is also common as food fuels our energy level. Be aware though that some anorexics feel an incredible high from not eating, analogous to the feeling induced by certain drugs.