BACKGROUND & AIMS: Malnutrition 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 (HPAQ(modified)), in long-term survivors after gastrectomy for gastric carcinoma, using doubly labelled water as reference method.

METHODS: Total energy expenditure (TEE) was estimated by DLW (14 days), ActiReg (3 days) and HPAQ(modified) (7 days) in 15 patients. Measurements were repeated after 12 months. Basal metabolic rate was measured with indirect calorimetry.

RESULTS: ActiReg and HPAQ(modified) both underestimated TEE by 180 (+/-254 SD) and 130 (+/-326 SD)kcalday(-1), i.e. 14% vs. 12%, respectively. However, this was evident only at higher levels of physical activity (PAL(DLW)> or =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 HPAQ(modified).

CONCLUSION: Both 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.