title: Online dietary intake estimation: reproducibility and validity of the Food4Me food frequency questionnaire against a 4-day weighed food record.
abstract: BACKGROUND
  Advances in nutritional assessment are continuing to embrace developments in computer technology. The online Food4Me food frequency questionnaire (FFQ) was created as an electronic system for the collection of nutrient intake data. To ensure its accuracy in assessing both nutrient and food group intake, further validation against data obtained using a reliable, but independent, instrument and assessment of its reproducibility are required.
  
  
  OBJECTIVE
  The aim was to assess the reproducibility and validity of the Food4Me FFQ against a 4-day weighed food record (WFR).
  
  
  METHODS
  Reproducibility of the Food4Me FFQ was assessed using test-retest methodology by asking participants to complete the FFQ on 2 occasions 4 weeks apart. To assess the validity of the Food4Me FFQ against the 4-day WFR, half the participants were also asked to complete a 4-day WFR 1 week after the first administration of the Food4Me FFQ. Level of agreement between nutrient and food group intakes estimated by the repeated Food4Me FFQ and the Food4Me FFQ and 4-day WFR were evaluated using Bland-Altman methodology and classification into quartiles of daily intake. Crude unadjusted correlation coefficients were also calculated for nutrient and food group intakes.
  
  
  RESULTS
  In total, 100 people participated in the assessment of reproducibility (mean age 32, SD 12 years), and 49 of these (mean age 27, SD 8 years) also took part in the assessment of validity. Crude unadjusted correlations for repeated Food4Me FFQ ranged from .65 (vitamin D) to .90 (alcohol). The mean cross-classification into "exact agreement plus adjacent" was 92% for both nutrient and food group intakes, and Bland-Altman plots showed good agreement for energy-adjusted macronutrient intakes. Agreement between the Food4Me FFQ and 4-day WFR varied, with crude unadjusted correlations ranging from .23 (vitamin D) to .65 (protein, % total energy) for nutrient intakes and .11 (soups, sauces and miscellaneous foods) to .73 (yogurts) for food group intake. The mean cross-classification into "exact agreement plus adjacent" was 80% and 78% for nutrient and food group intake, respectively. There were no significant differences between energy intakes estimated using the Food4Me FFQ and 4-day WFR, and Bland-Altman plots showed good agreement for both energy and energy-controlled nutrient intakes.
  
  
  CONCLUSIONS
  The results demonstrate that the online Food4Me FFQ is reproducible for assessing nutrient and food group intake and has moderate agreement with the 4-day WFR for assessing energy and energy-adjusted nutrient intakes. The Food4Me FFQ is a suitable online tool for assessing dietary intake in healthy adults.
authors.affiliation: Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, Department of Food and Nutritional Sciences, University of Reading, Reading, United Kingdom.
authors.forename: Rosalind
authors.identifier: http://orcid.org/0000-0003-3734-6489
authors.initials: R
authors.lastname: Fallaize
authors.forename: Hannah
authors.identifier: http://orcid.org/0000-0001-5944-8027
authors.initials: H
authors.lastname: Forster
authors.forename: Anna L
authors.identifier: http://orcid.org/0000-0003-0368-9336
authors.initials: AL
authors.lastname: Macready
authors.forename: Marianne C
authors.identifier: http://orcid.org/0000-0002-6651-2434
authors.initials: MC
authors.lastname: Walsh
authors.forename: John C
authors.identifier: http://orcid.org/0000-0003-3406-3002
authors.initials: JC
authors.lastname: Mathers
authors.forename: Lorraine
authors.identifier: http://orcid.org/0000-0002-7711-7499
authors.initials: L
authors.lastname: Brennan
authors.forename: Eileen R
authors.identifier: http://orcid.org/0000-0001-9465-052X
authors.initials: ER
authors.lastname: Gibney
authors.forename: Michael J
authors.identifier: http://orcid.org/0000-0001-5250-361X
authors.initials: MJ
authors.lastname: Gibney
authors.forename: Julie A
authors.identifier: http://orcid.org/0000-0001-7633-9455
authors.initials: JA
authors.lastname: Lovegrove
mesh_terms: D000293:Adolescent; D000328:Adult; D004032:Diet; D015930:Diet Records; D002149:Energy Intake; D005260:Female; D005502:Food; D006801:Humans; D016014:Linear Models; D008297:Male; D015596:Nutrition Assessment; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Food4Me; Web-based; dietary assessment; food frequency questionnaire; reproducibility; validity; weighed food record
references.citation: Nutr Cancer. 1990;13(4):281-92
references.pmid: 2345706
references.citation: Public Health Nutr. 2003 May;6(3):313-21
references.pmid: 12740081
references.citation: J Am Diet Assoc. 2008 Mar;108(3):539-43
references.pmid: 18313437
references.citation: Public Health Nutr. 2002 Aug;5(4):567-87
references.pmid: 12186666
references.citation: Proc Nutr Soc. 2004 Nov;63(4):537-47
references.pmid: 15831125
references.citation: Public Health Nutr. 2005 Oct;8(7A):1133-52
references.pmid: 16277825
references.citation: Eur J Clin Nutr. 2012 Feb;66(2):166-73
references.pmid: 21934698
references.citation: Eur J Clin Nutr. 1991 Dec;45(12):569-81
references.pmid: 1810719
references.citation: J Am Diet Assoc. 1998 Oct;98(10):1163-5
references.pmid: 9787724
references.citation: Int J Epidemiol. 1997;26 Suppl 1:S59-70
references.pmid: 9126534
references.citation: J Med Internet Res. 2012 Feb 21;14(1):e32
references.pmid: 22353433
references.citation: J Med Internet Res. 2013 Jun 05;15(6):e109
references.pmid: 23739995
references.citation: Lancet. 1986 Feb 8;1(8476):307-10
references.pmid: 2868172
references.citation: Am J Clin Nutr. 1999 Feb;69(2):243-9
references.pmid: 9989687
references.citation: Am J Epidemiol. 1992 Jul 15;136(2):192-200
references.pmid: 1415141
references.citation: J Med Internet Res. 2014 Jun 09;16(6):e150
references.pmid: 24911957
references.citation: Clin Nutr. 2014 Oct;33(5):906-14
references.pmid: 24144913
references.citation: Eur J Clin Nutr. 2004 Apr;58(4):594-604
references.pmid: 15042127
references.citation: Public Health Nutr. 2009 May;12(5):651-9
references.pmid: 18547450
references.citation: Am J Epidemiol. 1982 Apr;115(4):492-505
references.pmid: 7041631
references.citation: J Epidemiol Community Health. 2005 Dec;59(12):1054-7
references.pmid: 16286493
references.citation: Public Health Nutr. 2006 Feb;9(1):84-93
references.pmid: 16480538
references.citation: Diabetes Care. 1995 Sep;18(9):1249-54
references.pmid: 8612438
references.citation: Am J Epidemiol. 1995 Dec 1;142(11):1231-5
references.pmid: 7485070
references.citation: Nutrition. 2011 Jun;27(6):641-6
references.pmid: 20869207
references.citation: Am J Epidemiol. 1992 May 15;135(10):1114-26; discussion 1127-36
references.pmid: 1632423
references.citation: J Am Diet Assoc. 2007 Apr;107(4):605-10
references.pmid: 17383266
references.citation: Ann Epidemiol. 2001 Aug;11(6):417-27
references.pmid: 11454501
references.citation: Eur J Epidemiol. 1995 Apr;11(2):163-70
references.pmid: 7672070
references.citation: BMJ. 1990 Mar 17;300(6726):708-12
references.pmid: 2386561
references.citation: J Am Diet Assoc. 1993 Jul;93(7):790-6
references.pmid: 8320406
references.citation: J Public Health (Oxf). 2011 Dec;33(4):527-35
references.pmid: 21562029
references.citation: Nutr J. 2004 Sep 13;3:13
references.pmid: 15363100
references.citation: Public Health Nutr. 2014 Jul;17(7):1459-66
references.pmid: 23782894
references.citation: Nutr Res Rev. 2004 Jun;17(1):5-22
references.pmid: 19079912
references.citation: Int J Obes (Lond). 2012 May;36(5):675-85
references.pmid: 21694698
references.citation: J Med Internet Res. 2009 Oct 23;11(4):e43
references.pmid: 19861297