The influence of age and body mass index on relative accuracy of energy intake among Japanese adults.

OBJECTIVE To examine relationships between the ratio of energy intake to basal metabolic rate (EI/BMR) and age and body mass index (BMI) among Japanese adults. DESIGN Energy intake was assessed by 4-day semi-weighed diet records in each of four seasons (16 days in total). The EI/BMR ratio was calculated from reported energy intake and estimated basal metabolic rate as an indicator of reporting accuracy. SETTING Residents in three areas in Japan, namely Osaka (urban), Nagano (rural inland) and Tottori (rural coastal). SUBJECTS One hundred and eighty-three healthy Japanese men and women aged > or =30 years. RESULTS The oldest age group (> or =60 years) had higher EI/BMR values than the youngest age group (30-39 years) in both sexes (1.74 vs. 1.37 for men; 1.65 vs. 1.43 for women). In multiple regression analyses, age correlated positively (partial correlation coefficient, beta = 0.012, P < 0.001 for men; beta = 0.011, P < 0.001 for women) and BMI correlated negatively (beta = -0.031, P < 0.001 for men; beta = -0.025, P < 0.01 for women) with EI/BMR. CONCLUSION Age and BMI may influence the relative accuracy of energy intake among Japanese adults.