Essential fatty acid status in teenage girls with eating disorders and weight loss

Aim: To explore the relationship between essential fatty acids (FA) and weight changes in adolescent girls with eating disorders (ED). Methods: Blood samples were obtained from 220 girls with ED and 39 healthy controls. The girls with ED were 15.3 +/- 1.5 years of age and weighed 49.8 +/- 8.7 kg (BMI 18.3 +/- 2.8 kg/m2) after a weight loss of 6.8 +/- 6.4 kg. FA were analysed in plasma phospholipids (PPL) and erythrocyte membranes (ERY). Results: The proportions of saturated and monounsaturated FA were increased during weight loss, while linoleic acid (18:2 omega 6) was decreased. The proportions of eicosapentanoic acid (EPA) (20:5 omega 3) and docosahexanoic acid (DHA) (22:6 omega 3) in PPL and ERY did not differ from controls. The activity of stearoyl-CoA-desaturase was increased as evidenced by an increased product/precursor ratio and correlated with the rate of weight loss. The activities of delta-6-desaturase and delta-5-desaturase did not differ from controls. The rate of weight loss was inversely correlated with delta-6-desaturase and directly correlated with delta-5-desaturase. Conclusion: The FA profile indicates low-fat intake, fat mobilization from stores and an increased conversion of essential FA at the delta-5-desaturase step during weight loss in adolescent girls with ED. Normal levels of EPA and DHA were maintained.