Accuracy of food intake reporting in obese subjects with metabolic risk factors

Abstract

The aim of the present study was to determine the accuracy of reported energy intake according to a food-frequency questionnaire (FFQ) and dietary records (DR) in obese subjects with metabolic syndrome risk factors. Subjects were twenty-three men and twenty-seven women with mean BMI of 35·7 (range 30·5–43·8) kg/m 2 who participated in a dietary interview based on a FFQ and completed weighed DR. Total energy expenditure was measured with the doubly labelled water method. Total energy expenditure, measured RMR and physical activity level did not differ between under-reporters (50% of the sample) and non-under-reporters. Under-reporters had lower median intake of sweets, desserts and snacks than non-under-reporters (100 V. . 161g/d ( P =0·0008) and 61 V. . 128g/d ( P. =0·0002) according to the FFQ and DR, respectively). The DR also showed lower energy density (6·7 (sd 1·3) V 7·9 (sd 1·6) kJ/g; P =0·0064), lower intake of sugary drinks (0 V . 167g/d; P =0·0063) and higher scores for dietary restraint (9·0 (sd 5·0) V . 6·1 (sd 3·5); P =0·0285) in under-reporters. Energy density was associated with accuracy according to the FFQ (Spearman's rank correlation coefficient ( R S ) 0·406; P =0·0034) and the DR ( R S 0·537; P <0·0001). In multivariate analysis, consumption of bread and sweets, desserts and snacks measured by the FFQ was positively associated with accuracy ( I 2 adjusted 0·46 (95% CI 0·32, 0·70)). According to the DR, consumption of sweets, desserts and snacks was also associated with accuracy, as was dietary restraint (inversely) ( I 2 adjusted 0·67 (95% CI 0·54, 0·83)). In obese subjects with metabolic risk factors, intake of sweets, desserts and snacks, bread and dietary restraint were determinants of reporting accuracy.