Zinc status and meat avoidance in anorexia nervosa

The objective was to investigate the prevalence of meat avoidance and the zinc status of anorexia nervosa (AN) patients. Methods: 45 consecutive patients were recruited at admission to an eating disorder out-patient clinic. Acceptance criteria were illness of less than 30 months of duration without previous hospitalization. Intake and nutritional evaluation were routine except for additional questions on meat avoidance. A fasting plasma zinc test was done close to admission. Urinary zinc excretion was determined for eight patients. One hundred and fifty-six healthy subjects matched for age and demographic characteristics served as controls for meat avoidance, and another eight healthy girls were tested for plasma zinc. Ninety-six percent of patients avoided beef, and 75% avoided both beef and poultry. Meat avoidance was 6.5 times more prevalent among patients than controls. Twenty-five of the 45 patients (56%) became vegetarians several years prior to the onset of AN, at the mean age of 11.1 years. Reported reason for meat avoidance was aversion of varying degree. These "early meat avoiders" were compared with the 20 late avoiders and non-avoiders. Plasma zinc was deficient and identical for both groups of patients (56.3 ± 10.2 mcg/dl) and statistically different from controls (p<0.01). Twenty-four-hour urinary zinc excretion of eight patients was in the deficient range (140.3 ± 86.2 mcg/24 hr). At admission all patients were zinc deficient, independent of diet status. We speculate that zinc deficiency may predate the onset of AN, possibly originating during the adolescent growth spurt, and may cause MA through alterations in the sense of taste. Early MA is then likely to perpetuate low zinc status, destabilize normal eating patterns, and facilitate the development of an eating disorder. Vegetarianism in growing girls may be seen as a symptom of zinc deficiency.