RELATIVE AND BIOMARKER-BASED VALIDITY OF A FOOD-FREQUENCY QUESTIONNAIRE ESTIMATING INTAKE OF FATS AND CHOLESTEROL

The relative validity of a 104-item food-frequency method to assess in takes of fats and cholesterol was tested against the dietary history o f 191 men and women. Pearson correlation coefficients ranged from 0.38 for linoleic acid (% of energy) to O.83 for energy intake, with 0.78 and 0.75 for the intakes of total fat and saturated fatty acids, respe ctively. Mean intakes were overestimated by the food-frequency questio nnaire relative to the dietary history by 5% for energy and monounsatu rated fatty acids (% of energy) and up to 30% for linoleic acid intake . Linoleic acid concentrations in erythrocytes and adipose tissue were used as biomarkers of intake. The correlation of the linoleic acid in take according to the food-frequency questionnaire with linoleic acid in erythrocytes and adipose tissue was 0.44 and 0.28, respectively, an d the dietary history gave similar values. The food-frequency question naire gives results similar to those from the dietary history and is t hus considered appropriate for classifying subjects according to their fat intake.