Validity of the ActiReg® system and a physical activity interview in assessing total energy expenditure in long-term survivors after total gastrectomy

SummaryBackground & aimsMalnutrition is common after total gastrectomy. There is a need for clinically useful methods to assess energy requirements. We aimed to validate measurements of energy expenditure by an activity monitor (ActiReg®) and a physical activity interview (HPAQmodified), in long-term survivors after gastrectomy for gastric carcinoma, using doubly labelled water as reference method.MethodsTotal energy expenditure (TEE) was estimated by DLW (14 days), ActiReg® (3 days) and HPAQmodified (7 days) in 15 patients. Measurements were repeated after 12 months. Basal metabolic rate was measured with indirect calorimetry.ResultsActiReg® and HPAQmodified both underestimated TEE by 180 (±254 SD) and 130 (±326 SD) kcal day−1, i.e. 14% vs. 12%, respectively. However, this was evident only at higher levels of physical activity (PALDLW ≥ 1.65), whereas at lower levels (PAL < 1.65) no difference was found. There were no changes in TEE over time independent of the method used. DLW and ActiReg® had approximately the same width of the 95% confidence interval of this estimate, while it was 2.4 times larger by HPAQmodified.ConclusionBoth simple methods underestimated total energy expenditure at higher, but not at lower physical activity levels. The ActiReg® method appears useful to estimate changes in TEE over time.