Underreporting of energy intake among Japanese women aged 18–20 years and its association with reported nutrient and food group intakes

Abstract

AbstractObjectives:To evaluate the ratio of energy intake to basal metabolic rate (EI/BMR) among young female Japanese adults, and to compare the lifestyle and dietary characteristics between relatively low and high reporters.Design:Dietary intakes were assessed over a 1-month period with a validated, self-administered, diet history questionnaire, and lifestyle variables were assessed by a second questionnaire designed for this survey. The ratio of EI/BMR was calculated from reported energy intake and estimated basal metabolic rate.Subjects:In total, 1889 female Japanese university students aged 18–20 years who were enrolled in dietetics courses.Results:Ninety-five per cent of the subjects were classified into a non-obese group (body mass index (BMI) <25 kg m−2; mean±standard deviation (SD): 20.8±2.6 kg m−2). EI/BMR was 1.43±0.40 (mean±SD). Sixty-eight per cent of the subjects showed an EI/BMR level below the possibly balanced value of 1.56, 37% showed EI/BMR below the minimum survival value of 1.27 and 2% of the subjects showed EI/BMR exceeding the maximum value for a sustainable lifestyle of 2.4. BMI, body weight and BMR decreased significantly with the increase in EI/BMR (P<0.001). The percentage of energy from carbohydrate was significantly higher, whereas those from fat and protein were significantly lower, among the lower EI/BMR groups. As for food groups, a significantly declining trend from the lowest to the highest EI/BMR groups was observed for cereals.Conclusion:Underreporting, rather than overreporting, of energy intake was predominant in this relatively lean Japanese female population. BMI was the most important factor affecting the reporting accuracy of energy intake.