Information on a whole array of characteristics associated with dietary misreporting in a representative sample in each country is still limited. Using data from the 2012 National Health and Nutrition Survey, Japan, we investigated the prevalence and characteristics of under- and over-reporting of energy intake among 19,986 Japanese adults aged >=20 years.
Each individual's energy intake was calculated based on a 1-day semi-weighed dietary record. Under-, plausible, and over-reporters were identified based on the 95% confidence limits 1) for agreement between the ratio of energy intake to basal metabolic rate and a physical activity level for sedentary lifestyle (1.55), and 2) of the expected ratio of energy intake to estimated energy requirement of 1.0, assuming 'low active' level of physical activity.
Almost all subjects (>=92.8%) were classified as plausible reporters by any of the methods applied, with very low percentages of under- and over-reporters (<=6.3% and <=2.0%, respectively). Under-reporting was associated with younger age, overweight and obesity (compared with normal weight), current smoking (compared with never smoking), no alcohol drinking (compared with drinking everyday), and household consisting of a single person (compared with that consisting of two persons). Over-reporting was associated with gender (female), normal weight (compared with overweight), and household consisting of a single person.
Overall mean energy intake obtained in this sample of Japanese adults appears to be plausible, but caution should be exercised when assessing the plausibility of energy intake in some subgroups.