[Determination of the missrreporting of energy intake by Goldberg and Black in the FACSA cohort. Pilot study.].

INTRODUCTION: the Goldberg and Black method estimates dietary underreporting in epidemiological food consumption studies. This method compares the self-reported energy intake of the subjects with the estimate of their total energy expenditure.

OBJECTIVE: to evaluate underreporting and overreporting at individual and group levels in Health Sciences students.

MATERIAL AND METHODS: the study was cross-sectional and prospective; the participants recorded their food consumption through two dietary records, one on the weekend and the other on the weekdays. They previously answered to sign an informed consent letter, after which the physical activity questionnaire (IPAQ) they were also weighed and measured, and then the basal metabolic rate (BMR) was estimated, It calculated later the declared intake (EI)/BMR ratio, and finally, the cut-off points to determine under-declarers, over declarators and plausible declarators.

RESULTS: we found 14.81 % underreporting at the individual level and 44.44 % at the group level. The subjects with a higher BMI and those who performed strenuous physical activity were the ones who underreported the most. The subjects underreported performed moderate and severe physical activity at the group level.

CONCLUSIONS: it is crucial to carry out this methodology to verify the results of dietary evaluation since underreporting affects the estimation of nutrient intake and can alter the associations between diet and diseases in epidemiological studies.