title: Dietary intake reports fidelity--fact or fiction?
abstract: OBJECTIVE
  Bias is common in the assessment of self-reported dietary intake and physical activity. Little is known about the reasons for this underreporting, which is obtained even from rural individuals and lean subjects.
  
  
  METHODS
  Healthy volunteers (16 males, aged 18-55 years) were given two different full diets (high and low in saturated fat), each for a period of 4 weeks.
  
  
  RESULTS
  The subjects were able to provide a report of their dietary intake with relatively high accuracy (68.4%) on day one. Accuracy declined on day two (64.2%), and on day three, the reporting accuracy was only 55.0% (p<0.05). Interestingly, on day one, individuals were more precise (p<0.05) in their dietary reports if they had consumed an unhealthy diet high in saturated fat (72.5%) than a healthy diet high in unsaturated fat (64.4%). The most frequently omitted items were fruits and vegetables. The non-reporting of food items consumed is very high, even in the short term, and individuals tend to remember unhealthy items better.
  
  
  CONCLUSIONS
  Our pilot study showed that the inaccuracy of self-reported data includes not only the underestimation of energy intake (portion size) but also inaccurate qualitative data.
authors.affiliation: Institute for Clinical and Experimental Medicine, Prague, Czech Republic. pasu@ikem.cz
authors.forename: Pavel
authors.initials: P
authors.lastname: Suchanek
authors.forename: Rudolf
authors.initials: R
authors.lastname: Poledne
authors.forename: Jaroslav A
authors.initials: JA
authors.lastname: Hubacek
mesh_terms: D000293:Adolescent; D000328:Adult; D015982:Bias; D004032:Diet; D004034:Diet Surveys / Q000592:standards* / Q000706:statistics & numerical data; D004435:Eating; D002149:Energy Intake; D005227:Fatty Acids; D005638:Fruit; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012424:Rural Population; D014675:Vegetables; D055815:Young Adult
chemical_list: D005227:Fatty Acids