Dietary reporting errors on 24 h recalls and dietary questionnaires are associated with BMI across six European countries as evaluated with recovery biomarkers for protein and potassium intake

Br J Nutr. 2012 Mar;107(6):910-20. doi: 10.1017/S0007114511003564. Epub 2011 Jul 27.


Whether there are differences between countries in the validity of self-reported diet in relation to BMI, as evaluated using recovery biomarkers, is not well understood. We aimed to evaluate BMI-related reporting errors on 24 h dietary recalls (24-HDR) and on dietary questionnaires (DQ) using biomarkers for protein and K intake and whether the BMI effect differs between six European countries. Between 1995 and 1999, 1086 men and women participating in the European Prospective Investigation into Cancer and Nutrition completed a single 24-HDR, a DQ and one 24 h urine collection. In regression analysis, controlling for age, sex, education and country, each unit (1 kg/m²) increase in BMI predicted an approximately 1·7 and 1·3 % increase in protein under-reporting on 24-HDR and DQ, respectively (both P < 0·0001). Exclusion of individuals who probably misreported energy intake attenuated BMI-related bias on both instruments. The BMI effect on protein under-reporting did not differ for men and women and neither between countries on both instruments as tested by interaction (all P>0·15). In women, but not in men, the DQ yielded higher mean intakes of protein that were closer to the biomarker-based measurements across BMI groups when compared with 24-HDR. Results for K were similar to those of protein, although BMI-related under-reporting of K was of a smaller magnitude, suggesting differential misreporting of foods. Under-reporting of protein and K appears to be predicted by BMI, but this effect may be driven by 'low-energy reporters'. The BMI effect on under-reporting seems to be the same across countries.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Attitude to Health
  • Bias
  • Biomarkers / urine
  • Body Mass Index*
  • Cross-Sectional Studies
  • Diet / adverse effects
  • Diet / psychology*
  • Dietary Proteins / administration & dosage*
  • Energy Intake
  • Europe / epidemiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nutrition Assessment*
  • Overweight / epidemiology
  • Overweight / psychology
  • Overweight / urine
  • Potassium, Dietary / administration & dosage*
  • Prospective Studies
  • Self Report
  • Sex Characteristics
  • Statistics as Topic


  • Biomarkers
  • Dietary Proteins
  • Potassium, Dietary