Concurrent comparison of energy intake and expenditure among adults in Butajira District, Ethiopia

OBJECTIVE: To estimate and compare dietary energy intake (DEI) and total energy expenditure (TEE) among adults, using questionnaires. DESIGN: Comparative, cross-sectional study. SETTING: Community-based, at the demographic surveillance site (DSS) in Butajira District of Ethiopia. SUBJECTS: A total of 619 adults, 18-64 years of age, were randomly selected from among the urban and rural population of Butajira using the DSS sampling frame. Habitual dietary intake and physical activity were assessed using questionnaires. BMR was estimated using a regression equation, and TEE was calculated from BMR and the metabolic energy equivalent task (MET) and duration of reported activities. Physical activity level (PAL) was calculated as TEE/BMR, while food intake level (FIL) was calculated as DEI/BMR. The mean DEI:TEE ratio was used to evaluate reported DEI at the population level, while individual misreporters were identified by applying the Goldberg cut-off points at three levels of PAL. RESULTS: Based on the Goldberg method, 57% of the study participants were identified as acceptable reporters of DEI, among whom mean TEE was 8.21 (95% CI 8.01, 8.42) MJ (1963 (95% CI 1914, 2012) kcal), mean DEI was 8.13 (95% CI 7.93, 8.34) MJ (1944 (95% CI 1895, 1993) kcal) and mean DEI:TEE was 1.01 (95% CI 0.99, 1.04). CONCLUSION: The dietary history and physical activity questionnaires provide comparable estimates of mean energy intake and expenditure at a population level. Acceptable reporters have to be identified in order to obtain better estimates. Questionnaire-based estimates of energy intake should not be interpreted without an inherent system of comparison or validation.