title: Diet misreporting can be corrected: confirmation of the association between energy intake and fat-free mass in adolescents.
abstract: Subjective energy intake (sEI) is often misreported, providing unreliable estimates of energy consumed. Therefore, relating sEI data to health outcomes is difficult. Recently, Börnhorst et al. compared various methods to correct sEI-based energy intake estimates. They criticised approaches that categorise participants as under-reporters, plausible reporters and over-reporters based on the sEI:total energy expenditure (TEE) ratio, and thereafter use these categories as statistical covariates or exclusion criteria. Instead, they recommended using external predictors of sEI misreporting as statistical covariates. We sought to confirm and extend these findings. Using a sample of 190 adolescent boys (mean age=14), we demonstrated that dual-energy X-ray absorptiometry-measured fat-free mass is strongly associated with objective energy intake data (onsite weighted breakfast), but the association with sEI (previous 3-d dietary interview) is weak. Comparing sEI with TEE revealed that sEI was mostly under-reported (74 %). Interestingly, statistically controlling for dietary reporting groups or restricting samples to plausible reporters created a stronger-than-expected association between fat-free mass and sEI. However, the association was an artifact caused by selection bias - that is, data re-sampling and simulations showed that these methods overestimated the effect size because fat-free mass was related to sEI both directly and indirectly via TEE. A more realistic association between sEI and fat-free mass was obtained when the model included common predictors of misreporting (e.g. BMI, restraint). To conclude, restricting sEI data only to plausible reporters can cause selection bias and inflated associations in later analyses. Therefore, we further support statistically correcting sEI data in nutritional analyses. The script for running simulations is provided.
authors.affiliation: 1Institute of Psychology,University of Tartu,Näituse 2,50410,Tartu,Estonia.
authors.forename: Uku
authors.initials: U
authors.lastname: Vainik
authors.affiliation: 1Institute of Psychology,University of Tartu,Näituse 2,50410,Tartu,Estonia.
authors.forename: Kenn
authors.initials: K
authors.lastname: Konstabel
authors.affiliation: 4Faculty of Exercise and Sport Sciences,University of Tartu,Jakobi 5,51014,Tartu,Estonia.
authors.forename: Evelin
authors.initials: E
authors.lastname: Lätt
authors.affiliation: 4Faculty of Exercise and Sport Sciences,University of Tartu,Jakobi 5,51014,Tartu,Estonia.
authors.forename: Jarek
authors.initials: J
authors.lastname: Mäestu
authors.affiliation: 4Faculty of Exercise and Sport Sciences,University of Tartu,Jakobi 5,51014,Tartu,Estonia.
authors.forename: Priit
authors.initials: P
authors.lastname: Purge
authors.affiliation: 4Faculty of Exercise and Sport Sciences,University of Tartu,Jakobi 5,51014,Tartu,Estonia.
authors.forename: Jaak
authors.initials: J
authors.lastname: Jürimäe
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000294:Adolescent Behavior / Q000208:ethnology; D017195:Adolescent Nutritional Physiological Phenomena / Q000208:ethnology; D001823:Body Composition; D003198:Computer Simulation; D004032:Diet / Q000208:ethnology; D002149:Energy Intake / Q000208:ethnology; D004957:Estonia; D005240:Feasibility Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008954:Models, Biological; D041641:Musculoskeletal Development; D012574:Schools; D015983:Selection Bias; D057566:Self Report; D013223:Statistics as Topic
keywords:  EB% energy balance percentage;  PR plausible reporters;  TEE total energy expenditure;  UR under-reporters;  oEI objective energy intake;  sEI subjective energy intake; Dietary interviews; Objective energy intake; Plausible reporting; Selection bias; Subjective energy intake; Under-reporting