Original article
Higher Calorie Diets Increase Rate of Weight Gain and Shorten Hospital Stay in Hospitalized Adolescents With Anorexia Nervosa

https://doi.org/10.1016/j.jadohealth.2013.07.014Get rights and content

Abstract

Purpose

Current recommendations for refeeding in anorexia nervosa (AN) are conservative, beginning around 1,200 calories to avoid refeeding syndrome. We previously showed poor weight gain and long hospital stay using this approach and hypothesized that a higher calorie approach would improve outcomes.

Methods

Adolescents hospitalized for malnutrition due to AN were included in this quasi-experimental study comparing lower and higher calories during refeeding. Participants enrolled between 2002 and 2012; higher calories were prescribed starting around 2008. Daily prospective measures included weight, heart rate, temperature, hydration markers and serum phosphorus. Participants received formula only to replace refused food. Percent Median Body Mass Index (%MBMI) was calculated using 50th percentile body mass index for age and sex. Unpaired t-tests compared two groups split at 1,200 calories.

Results

Fifty-six adolescents with mean (±SEM) age 16.2 (±.3) years and admit %MBMI 79.2% (±1.5%) were hospitalized for 14.9 (±.9) days. The only significant difference between groups (N = 28 each) at baseline was starting calories (1,764 [±60] vs. 1,093 [±28], p < .001). Participants on higher calories had faster weight gain (.46 [±.04] vs. .26 [±.03] %MBMI/day, p < .001), greater daily calorie advances (122 [±8] vs. 98 [±6], p = .024), shorter hospital stay (11.9 [±1.0] vs. 17.6 [±1.2] days, p < .001), and a greater tendency to receive phosphate supplementation (12 vs. 8 participants, p = .273).

Conclusions

Higher calorie diets produced faster weight gain in hospitalized adolescents with AN as compared with the currently recommended lower calorie diets. No cases of the refeeding syndrome were seen using phosphate supplementation. These findings lend further support to the move toward more aggressive refeeding in AN.

Section snippets

Study design and participants

This prospective observational study used a quasi-experimental design to compare a lower calorie group (800–1,200 calories) including former study participants as historical controls and higher calorie group (1,400–2,400 calories) including newly enrolled participants. Participants were age 9–20 years old, diagnosed with AN [15], met criteria for hospitalization [16] and had no previous admissions for AN. Exclusion criteria included pregnancy, diagnosis of bulimia nervosa, and/or thought

Results

We followed 56 adolescents over a mean (±SEM) of 14.9 (±.9) days. The overall study population was 98% female, mean age 16.2 (±.3) years (12.3–20.9), 76% non-Hispanic white, 6% Asian/Pacific Islander, and 19% other race/ethnicity. Mean %MBMI was 79.2 (±1.5), mean BMI was 16.1 (±.3) kg/m2 (range 11.1–21.8). Participants were bradycardic and hypothermic consistent with hospital admission criteria [16]. Markers of hydration status were within normal limits [20]. As shown in Table 1, the only

Discussion

This study compared moderately malnourished adolescents with AN during refeeding on higher calorie diets starting around 1,800 calories and advancing by about 120 calories per day in the first week versus lower calorie diets starting around 1,100 calories and advancing by approximately 100 calories per day. Our previously published [11] data from participants on lower calorie diets are included here for comparison, because these diets are still recommended and widely used in the United States

References (40)

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