Novel Anorexia Nervosa Refeeding Strategies: From Human to Rat and Back Again

Aims 1) To define changes in diet and physical activity (PA) that lead to inpatient treatment of anorexia nervosa (AN). 2) To use this data to refine a rat model of AN and examine the effects of a novel refeeding diet. Methods 1) 15 females, 12–18 years, completed a FFQ, 24h diet recall, Pediatric PA Recall, and Modifiable Activity Questionnaire to assess changes in diet and the PA that lead to inpatient admission. 2) AN was induced in rats via free access to a running wheel and 1h access to low fat (LF) diet per day. Rats were re‐fed either LF (15% fat, 15% protein; AN LF) or test (30% fat, 28% protein, 1% leucine; AN moderate fat, AN MF) diet. Controls (C) were identical to AN LF but with no access to a running wheel (no AN). Body fat (BF) was assessed by QMR and fat pad weights. Energy balance was measured via indirect calorimetry. Results 1) PA increased 300% prior to inpatient admission without any change in energy or macronutrient intake. 2) AN LF recovered 100% of initial weight after 7d of refeeding (8% BF) whereas AN MF did not return to 100% weight (4% BF) due to a 50% decrease in energy intake in AN MF vs AN LF with no difference in total energy expenditure. AN LF rats had fatty liver and higher visceral fat content than both C and AN MF. Conclusions 1) Increased PA, not decreased energy intake, precipitated hospitalization for AN. 2) MF is not a dietary treatment for AN. However, LF diet causes fatty liver and visceral fat accumulation.