Television arrived in a Fijian province, and within three years purging appeared among teenage girls
A survey in Nadroga, Fiji, found that no teenage schoolgirls reported purging in 1995, just weeks after television came to the province. By 1998 the figure was 11.3%. The finding is one strand of evidence that bulimia nervosa grows from a tangle of culture, genes, brain chemistry and self-esteem.
Bulimia nervosa is an eating disorder defined by episodes of eating large amounts while feeling out of control, followed by behaviour meant to prevent weight gain, such as vomiting or fasting. It runs in families, and estimates of the share of risk explained by genetics range widely, from 30% to 80%. Other risk factors include stress, low self-esteem, cultural pressure towards a particular body type, and parents who fixate on weight. Diagnosis is hard because people usually hide the behaviour.
Biology plays a large role. Many people with the condition struggle to recognise internal signals, so fullness may register late. Dieting lowers blood levels of tryptophan, a building block of serotonin, and experimentally depleting tryptophan can raise bulimic urges within hours in current and former patients. Brain imaging has found reduced brain volume that appears to reverse after long-term recovery. Comparisons with drug addiction have limited support, though some shared vulnerabilities in dopamine receptors have been reported.
The condition rarely travels alone. One study found that 70% of people with bulimia had experienced depression at some point, against 26% of women in the general population, rising to 88% for mood disorders overall. Researchers at the University of Cincinnati concluded that bipolar and eating disorders are clearly related. Physical effects include dangerous electrolyte imbalances that can disturb the heart, and acid erosion of the teeth.
Christopher Fairburn's cognitive-behavioural model, often treated as the gold standard, describes a self-perpetuating loop: worry about weight and low self-esteem produce rigid dieting rules; a small slip triggers all-or-nothing thinking and a binge; the binge prompts purging. Other researchers, Byrne and McLean, argue the loop can run the other way, with purging preceding bingeing. Critics note the model describes more than it explains, may not fit non-Western cultures, and cannot settle whether distorted thinking causes disordered eating or results from it.
Source: Bulimia
