UNDERREPORTING OF ENERGY-INTAKE IN 1-YEAR-OLD TO 18-YEAR-OLD GERMAN CHILDREN AND ADOLESCENTS

It is generally accepted that self-reported food intakes underestimate habitual energy intake (underreporting). Underreporting is often addr essed by computing the ratio of measured energy intake to predicted ba sal metabolic rate (EI:BMR). We used this ratio to study differences b etween not plausible records (NPR) and plausible records (PR) accordin g to recalculated cut-off values for EI:BMR ratios (< 0.97 to 1.07; ag e- and sex-dependent) in cross-sectional data of 1 032 3d weighed diet records of 1 to 18 year old children and adolescents. Underreporting (in 5 % of total subjects) was age and sex dependent: about 1 % in the 1 to 5 year old children, 2 % (3 %) in the 6 to 13 year old males (fe males) and 12 % (20 %) in the adolescent males (females), respectively . To analyse differences between subgroups with PR vs. NPR we therefor e concentrated on the 14 to 18 year olds. Male (female) subjects with NPR vs. PR had a 40 % lower total EI: 7.4 MJ/d (5.3 MJ/d) vs. 11.5 MJ/ d (8.0 MJ/d), respectively. In both sexes with NPR vs. PR, EI per meal was lower. Females with NPR vs. PR had a higher body mass index (kg:m (2)), recorded fewer meals per day, and had a shorter time span betwee n the first and last meal per day. Furthermore, females with NPR vs. P R had higher intakes per MJ of water, protein, fiber, sodium, iron, ni acin, zinc, and protein in percent of total EI, but a lower intake of added sugars per MJ. Males with NPR vs. PR answered significantly more often that they usually eat more, had a higher water intake per MJ, a nd a higher Ca:P. The observed differences between groups with PR and NPR indicate different food habits or dietary recording behavior. Ther efore, validity in dietary studies cannot be achieved by simply exclud ing underreporters.