EFFECT OF ADDITIONAL QUESTIONS ABOUT FAT ON THE VALIDITY OF FAT ESTIMATES FROM A FOOD FREQUENCY QUESTIONNAIRE

Objective: We studied whether the validity of fat estimates from food frequency questionnaires (FFQ) can be increased by using In nutrient c alculation an additional qualitative information about the type of fat and reduced consumption of visible fat and skin. Design: A random sam ple of women answered an 88-item self-administered FFQ and performed 4 x 1-week weighed dietary records (DR). Setting: Uppsala County in cen tral Sweden. Subjects: One hundred and eighty-four women aged 30-77 y, with FFQ and complete DR; 73 women with subcutaneous adipose tissue ( AT) samples. Methods: Fat intake from the FFQ was calculated with/with out use of qualitative information and compared to DR and fat composit ion of AT. Main outcome measures: Estimates of long-time intake of tot al fat, saturated, monounsaturated, polyunsaturated fat and ten specif ic fatty acids based on FFQ, DR and composition of AT. Results: Mean a bsolute fat intake estimates based on FFQ (without vs with use of addi tional fat information) were 21.2 vs 20.2 g/d for saturated, 17.1 vs 1 6.0 g/d for monounsaturated and 7.3 vs 7.3 g/d for polyunsaturated fat . The Pearson correlation coefficient between the FFQ and AT for polyu nsaturated fat was 0.65 vs 0.67, Corresponding correlation between the FFQ and DR was 0.40 vs 0.41; adjustment for energy intake increased t his correlation from 0.40 to 0.52. Conclusions: The increase in the va lidity of fat estimates due to use of qualitative information about fa t was negligible; energy adjustment had greater impact than asking add itional questions. Sponsorship: The study was supported by grants from the Swedish Cancer Society. Descriptors: fats; questionnaire: adipose tissue validity.