title: Underreporting of energy intake in Brazilian women varies according to dietary assessment: a cross-sectional study using doubly labeled water.
abstract: OBJECTIVE
  Underreporting of energy intake is prevalent in food surveys, but there is controversy about which dietary assessment method provides greater underreporting rates. Our objective is to compare validity of self-reported energy intake obtained by three dietary assessment methods with total energy expenditure (TEE) obtained by doubly labeled water (DLW) among Brazilian women.
  
  
  METHODS
  We used a cross-sectional study.
  
  
  METHODS
  Sixty-five females aged 18 to 57 years (28 normal-weight, 10 overweight, and 27 obese) were recruited from two universities to participate.
  
  
  METHODS
  TEE determined by DLW, energy intake estimated by three 24-hour recalls, 3-day food record, and a food frequency questionnaire (FFQ).
  
  
  METHODS
  Regression and analysis of variance with repeated measures compared TEE and energy intake values, and energy intake-to-TEE ratios and energy intake-TEE values between dietary assessment methods. Bland and Altman plots were provided for each method. chi(2) test compared proportion of underreporters between the methods.
  
  
  RESULTS
  Mean TEE was 2,622 kcal (standard deviation [SD]=490 kcal), while mean energy intake was 2,078 kcal (SD=430 kcal) for the diet recalls; 2,044 kcal (SD=479 kcal) for the food record and 1,984 kcal (SD=832 kcal) for the FFQ (all energy intake values significantly differed from TEE; P<0.0001). Bland and Altman plots indicated great dispersion, negative mean differences between measurements, and wide limits of agreement. Obese subjects underreported more than normal-weight subjects in the diet recalls and in the food records, but not in the FFQ. Years of education, income and ethnicity were associated with reporting accuracy.
  
  
  CONCLUSIONS
  The FFQ produced greater under- and overestimation of energy intake. Underreporting of energy intake is a serious and prevalent error in dietary self-reports provided by Brazilian women, as has been described in studies conducted in developed countries.
authors.affiliation: Department of Nutrition, University of Sao Paulo, Sao Paulo, Brazil. fernanda.scagliusi@gmail.com
authors.forename: Fernanda B
authors.initials: FB
authors.lastname: Scagliusi
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ferriolli
authors.forename: Karina
authors.initials: K
authors.lastname: Pfrimer
authors.forename: Cibele
authors.initials: C
authors.lastname: Laureano
authors.forename: Caroline Sanita
authors.initials: CS
authors.lastname: Cunha
authors.forename: Bruno
authors.initials: B
authors.lastname: Gualano
authors.forename: Barbara Hatzlhoffer
authors.initials: BH
authors.lastname: Lourenço
authors.forename: Antonio Herbert
authors.initials: AH
authors.lastname: Lancha
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001834:Body Water / Q000378:metabolism*; D001938:Brazil; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D003903:Deuterium; D015930:Diet Records; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D011939:Mental Recall; D008875:Middle Aged; D015596:Nutrition Assessment; D009765:Obesity / Q000523:psychology; D010103:Oxygen Isotopes; D012044:Regression Analysis; D012650:Self Disclosure; D011795:Surveys and Questionnaires / Q000592:standards; D013851:Thinness / Q000523:psychology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010103:Oxygen Isotopes; D003903:Deuterium