Abstract
In Western countries underestimation of energy intake (EI) is considered a serious problem in dietary surveys, but information on the accuracy of EI among Japanese people is sparse. We compared estimated EI with measured total energy expenditure (TEE) in 21 Japanese women aged 20-22y. Dietary intake was estimated by 7-d weighed dietary records (7dWR) and a self-administered diet history questionnaire (DHQ). TEE was mea-sured for 25±3d (mean±standard deviation, range: 16-27d) by a uniaxial accelerometer. Both El by 7dWR (1, 498±305kcal/d) and El by DHO (1, 599±331kcal/d) were signifi-cantly lower than TEE (1, 865±179kcal/d) (p<0.001 and p<0.01, respectively), but nei-ther estimated EI nor the magnitude of EI underestimation (20±15% for 7dWR and 13±23% for DHQ) was significantly different between two methods (p=0.25 and p=0.22, respectively). The Spearman correlation (r) between TEE and EI was 0.51 (p=0.02) for 7dWR and 0.09 (p=0.71) for DHQ, indicating better ranking of individuals by 7dWR. The accuracy of El (El/TEE) was negatively associated with the percentage of EI from protein in 7dWR (r=-0.44, p=0.049) and positively associated with the percentage of EI from fat in both 7dWR (r=0.45, p=0.04) and DHQ (r=0.62, p<0.01), suggesting selective overestima-tion of protein and selective underestimation of fat. These results indicate not only underes-timation of habitual EI but also selective under- and/or overestimation of macronutrients in both 7dWR and DHQ.
