Their study found decreased blood flow in a variety of brain areas in a group of adolescents with anorexia, but found that this was not actually linked to any features of the eating disorder, contrary to what the newspaper headline suggests:
There appears to be no association between this reduction in blood flow and cerebral dominance, nutritional status, length of illness, mood, or eating disorder psychopathology. However, there is a significant association between reduced blood flow and impaired visuospatial ability, impaired complex visual memory, and enhanced
This suggests that the underlying brain changes in anorexia do not directly affect eating, food or body perception – they are much more general.
How then, does this lead to anorexia ? Lask and his team suggest that a part of the brain called the limbic system might be involved, and that:
Within specific setting conditions such as sociocultural pressures to be thin and a driven and perfectionist personality, the limbic system imbalance may be triggered by such factors as puberty, dieting, weight loss, and various stressors.
In other words, without the pressures from society and a ‘perfectionist personality’, people who have these differences in brain function are unlikely to become anorexic. People who have both therefore, are at the greatest risk of wanting to starve themselves.
A recent study published in the British Journal of Psychology gives us a clue as to what might cause this pressure to be thin.
Researchers showed participants pictures of female bodies, digitally altered to be wider or more thin than average, and then asked them to pick out most attractive body shapes from a range.
After being shown thin bodies, participants tended to pick thinner bodies as the most attractive.
The authors argue that perception of attractiveness and beauty are relative to our experience of the most common body shape, suggesting that the promotion of thin bodies in the media may distort our idea of attractiveness by affecting the ‘data’ on which we judge normality.