Use of a triaxial accelerometer to validate reported food intakes

Abstract

Background: An easy and cheap method for validating reported energy intake (EI) is needed. Objective: Reported El was compared with calculated energy expenditure (EEcalc) and with energy expenditure measured by the doubly labeled water method (EEDLW). Design: EE was calculated on the basis of basal metabolic rate (BMR) measured with the ventilated-hood technique and physical activity (PA) measured with a triaxial accelerometer (EEVH+PA) and on the basis of BMR estimated by using World Health Organization equations and PA (EEWHO+PA): EEcalc = -1,259 + 1.55 x BMR + 0.076 x counts/min (r2 = 0.90, P = 0.0001). Subjects [n = 12 men and 12 women aged 60 ± 3 y; body mass index (in kg/m2): 26 ± 4] reported their food intakes for 7 d and EEDLW, EEVH+PA, and EEWHO+PA were assessed over the same 7 d. Results: Reported El (9.0 ± 2.1 MJ/d) was lower (P < 0.0001) than were EEDDLW (11.3 ± 2.3 MJ/d), EEVH+PA (10.8 ± 1.7 MJ/d), and EEWHO+PA (10.8 ± 1.8 MJ/d). Underreporting was 19.4 ± 14.0%, 16.7 ± 13.6%, and 16.4 ± 15.5% on the basis of EEDLW, EE VH+PA, and EEWHO+PA, respectively. The difference of 2.7 ± 8.0% between EEDLW and EEVH+PA was not related to the average of both percentages and was not significantly different from zero. The percentage of underreporting calculated with EEWHO+PA was not significantly different from that calculated with EEDLW. Conclusions: The use of a combination of BMR (measured or estimated) and PA is a good method for validating reported El. There was no significant difference between the percentage of underreporting calculated with EEVH+PA, EEWHO+PA, EEDLW.