title: Identifying sources of reporting error using measured food intake.
abstract: OBJECTIVE
  To investigate the magnitude and relative contribution of different sources of measurement errors present in the estimation of food intake via the 24-h recall technique.
  
  
  METHODS
  We applied variance decomposition methods to the difference between data obtained from the USDA's Automated Multiple Pass Method (AMPM) 24-h recall technique and measured food intake (MFI) from a 16-week cafeteria-style feeding study. The average and the variance of biases, defined as the difference between AMPM and MFI, were analyzed by macronutrient content, subject and nine categories of foods.
  
  
  METHODS
  Twelve healthy, lean men (age, 39+/-9 year; weight, 79.9+/-8.3 kg; and BMI, 24.1+/-1.4 kg/m2).
  
  
  RESULTS
  Mean food intakes for AMPM and MFI were not significantly different (no overall bias), but within-subject differences for energy (EI), protein, fat and carbohydrate intakes were 14, 18, 23 and 15% of daily intake, respectively. Mass (incorrect portion size) and deletion (subject did not report foods eaten) errors were each responsible for about one-third of the total error. Vegetables constituted 8% of EI but represented >25% of the error across macronutrients, whereas grains that contributed 32% of EI contributed only 12% of the error across macronutrients.
  
  
  CONCLUSIONS
  Although the major sources of reporting error were mass and deletion errors, individual subjects differed widely in the magnitude and types of errors they made.
authors.affiliation: Diet and Human Performance Laboratory, US Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD, USA. william.rumpler@ars.usda.gov
authors.forename: W V
authors.initials: WV
authors.lastname: Rumpler
authors.forename: M
authors.initials: M
authors.lastname: Kramer
authors.forename: D G
authors.initials: DG
authors.lastname: Rhodes
authors.forename: A J
authors.initials: AJ
authors.lastname: Moshfegh
authors.forename: D R
authors.initials: DR
authors.lastname: Paul
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015982:Bias; D003627:Data Interpretation, Statistical; D004034:Diet Surveys; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004435:Eating / Q000523:psychology*; D002523:Edible Grain; D002149:Energy Intake; D006801:Humans; D008297:Male; D011939:Mental Recall; D015596:Nutrition Assessment; D014675:Vegetables
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins