[Use of linear regression for correction of dietary data].

OBJECTIVE Methodological approaches have been developed to minimize effects of measurement error in dietary intake data. The objective of the study was to apply a strategy to correct intake data according to measurement error. METHODS Intake data were obtained by applying the Food Frequency Questionnaire in 79 adolescents of São Paulo city, Brazil. Correction of dietary intake data was performed by linear regression, after energy adjustment by the residual method. The reference method used was 24-hour dietary recall and it was applied three times. RESULTS Corrected values were similar to reference values. Correction factor gamma was 0.89 to energy. For macronutrients, factors were 0.41, carbohydrate 0.22, and lipid and protein 0.20. CONCLUSIONS Mean and standard deviation of corrected values show a correction for the measurement error. The performance of these methods, that are imperfect, is questioned when the assumptions are not proved which is common in intake studies of measures based on the reports of individuals.