title: Effect of additional questions about fat on the validity of fat estimates from a food frequency questionnaire. Study Group of MRS SWEA.
abstract: OBJECTIVE
  We studied whether the validity of fat estimates from food frequency questionnaires (FFQ) can be increased by using in nutrient calculation an additional qualitative information about the type of fat and reduced consumption of visible fat and skin.
  
  
  METHODS
  A random sample of women answered an 88-item self-administered FFQ and performed 4 x 1-week weighed dietary records (DR).
  
  
  METHODS
  Uppsala County in central Sweden.
  
  
  METHODS
  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/without use of qualitative information and compared to DR and fat composition of AT.
  
  
  METHODS
  Estimates of long-time intake of total fat, saturated, monounsaturated, polyunsaturated fat and ten specific fatty acids based on FFQ, DR and composition of AT.
  
  
  RESULTS
  Mean absolute fat intake estimates based on FFQ (without vs with use of additional fat information) were 21.2 vs 20.2 g/d for saturated, 17.1 vs 16.0 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 polyunsaturated 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 this correlation from 0.40 to 0.52.
  
  
  CONCLUSIONS
  The increase in the validity of fat estimates due to use of qualitative information about fat was negligible; energy adjustment had greater impact than asking additional questions.
authors.affiliation: Department of Medical Epidemiology, Karolinska Institute, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Wolk
authors.forename: H
authors.initials: H
authors.lastname: Ljung
authors.forename: B
authors.initials: B
authors.lastname: Vessby
authors.forename: D
authors.initials: D
authors.lastname: Hunter
authors.forename: W C
authors.initials: WC
authors.lastname: Willett
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D000368:Aged; D001823:Body Composition; D015992:Body Mass Index; D015930:Diet Records; D004041:Dietary Fats / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage; D005227:Fatty Acids / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008875:Middle Aged; D011897:Random Allocation; D011795:Surveys and Questionnaires
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid