Elevated BMI and Male Sex Are Associated with Greater Underreporting of Caloric Intake as Assessed by Doubly Labeled Water

Background: Inaccuracies in energy intake (EI) measurement hinder identification of risk factors that predict weight gain and evaluation of obesity prevention and treatment interventions. Research has used objective measures of EI to identify underreporting correlates, producing mixed results, suggesting the need to examine novel potential correlates.

Objective: With the use of an objective measure of EI from doubly labeled water (DLW) this report examined multiple potential underreporting correlates.

Methods: Adolescents from 2 studies (study 1, n = 91; mean age: 18.4 ± 0.58 y; 100% female; study 2, n = 162; mean age: 15.2 ± 1.99 y; 82 female adolescents; 80 male adolescents) completed a DLW assessment of EI, a food-frequency questionnaire, and measures of perceived pressure for thinness, thin-ideal internalization, body dissatisfaction, dieting, food-cue reactivity, eating disorder symptoms, socioeconomic status, and neural response to food; BMI (in kg/m(2)) was measured over a 2-y follow-up.

Results: Elevated BMI correlated with underreported EI in study 1 (r = 0.26, P < 0.05) and study 2 (r = 0.20, P = 0.01), as did male sex in study 2 (r = 0.24, P < 0.01); the other survey measures did not. Underreporting correlated negatively (r = -0.29; uncorr P < 0.001) with responsivity of brain regions implicated in motor control to palatable food receipt and positively (r = 0.31; uncorr P < 0.001) with responsivity of a region implicated in taste processing to cues signaling impending milkshake receipt. Underreporting did not predict future change in BMI in either study.

Conclusions: Findings document marked underreporting and replicate evidence that BMI correlates positively with underreporting and extends this literature by revealing that several novel factors were unrelated to underreporting and further that neural responsivity to food correlated with underreporting, suggesting that adolescents who showed reduced responsivity in a motor control region to food receipt and elevated responsivity of gustatory regions to anticipated palatable food receipt showed greater underreporting. This trial was registered at clinicaltrials.gov as NCT00433680 and NCT02084836.