How accurate are predictive formulas calculating energy expenditure in adolescent patients with anorexia nervosa?
OBJECTIVE
To compare resting energy expenditure, measured by indirect calorimetry, to values estimated by different predictive formulas in adolescent patients with anorexia nervosa.


METHODS
We studied 22 female in-patients with a mean age of 14.7 years (SD 1.2). Resting energy expenditure was measured by indirect calorimetry (Deltatrac II MBM-200). We compared measured resting energy expenditure to values estimated by several predictive formulas [Fleisch, Harris-Benedict, FAO, Schofield-HW, Schebendach] using the intraclass correlation coefficient and the Bland-Altman method.


RESULTS
Body mass index increased significantly (P<0.001). Measured resting energy expenditure increased during hospitalization (P<0.05). All formulas overestimated resting energy expenditure with respect to indirect calorimetry except the Schebendach formula. The intraclass correlation between indirect calorimetry and the formulas were poor (0.09-0.20). We observed a poor clinical agreement (Bland-Altman).


CONCLUSIONS
Body mass index and resting energy expenditure increased during hospitalization. The majority of the predictive formulas overestimate resting energy expenditure in adolescent patients with anorexia nervosa. Therefore, indirect calorimetry may be a very useful tool for calculating caloric requirements in these patients.
Cuerda
C
C
Nutrition Unit, Hospital General Universitario Gregorio Marañón, c/Doctor Esquerdo 46, 28007 Madrid, Spain. mcuerda.hgugm@salud.madrid.org
Ruiz
A
A
Velasco
C
C
Bretón
I
I
Camblor
M
M
García-Peris
P
P
D000293:Adolescent; D000856:Anorexia Nervosa / Q000378:metabolism* / Q000628:therapy*; D000886:Anthropometry; D001481:Basal Metabolism / Q000502:physiology*; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005526:Food, Formulated; D006801:Humans; D008433:Mathematics; D009751:Nutritional Requirements; D011237:Predictive Value of Tests; D011446:Prospective Studies