title: Short- and medium-term efficacy of a Web-based computer-tailored nutrition education intervention for adults including cognitive and environmental feedback: randomized controlled trial.
abstract: BACKGROUND
  Web-based, computer-tailored nutrition education interventions can be effective in modifying self-reported dietary behaviors. Traditional computer-tailored programs primarily targeted individual cognitions (knowledge, awareness, attitude, self-efficacy). Tailoring on additional variables such as self-regulation processes and environmental-level factors (the home food environment arrangement and perception of availability and prices of healthy food products in supermarkets) may improve efficacy and effect sizes (ES) of Web-based computer-tailored nutrition education interventions.
  
  
  OBJECTIVE
  This study evaluated the short- and medium-term efficacy and educational differences in efficacy of a cognitive and environmental feedback version of a Web-based computer-tailored nutrition education intervention on self-reported fruit, vegetable, high-energy snack, and saturated fat intake compared to generic nutrition information in the total sample and among participants who did not comply with dietary guidelines (the risk groups).
  
  
  METHODS
  A randomized controlled trial was conducted with a basic (tailored intervention targeting individual cognition and self-regulation processes; n=456), plus (basic intervention additionally targeting environmental-level factors; n=459), and control (generic nutrition information; n=434) group. Participants were recruited from the general population and randomly assigned to a study group. Self-reported fruit, vegetable, high-energy snack, and saturated fat intake were assessed at baseline and at 1- (T1) and 4-months (T2) postintervention using online questionnaires. Linear mixed model analyses examined group differences in change over time. Educational differences were examined with group×time×education interaction terms.
  
  
  RESULTS
  In the total sample, the basic (T1: ES=-0.30; T2: ES=-0.18) and plus intervention groups (T1: ES=-0.29; T2: ES=-0.27) had larger decreases in high-energy snack intake than the control group. The basic version resulted in a larger decrease in saturated fat intake than the control intervention (T1: ES=-0.19; T2: ES=-0.17). In the risk groups, the basic version caused larger decreases in fat (T1: ES=-0.28; T2: ES=-0.28) and high-energy snack intake (T1: ES=-0.34; T2: ES=-0.20) than the control intervention. The plus version resulted in a larger increase in fruit (T1: ES=0.25; T2: ES=0.37) and a larger decrease in high-energy snack intake (T1: ES=-0.38; T2: ES=-0.32) than the control intervention. For high-energy snack intake, educational differences were found. Stratified analyses showed that the plus version was most effective for high-educated participants.
  
  
  CONCLUSIONS
  Both intervention versions were more effective in improving some of the self-reported dietary behaviors than generic nutrition information, especially in the risk groups, among both higher- and lower-educated participants. For fruit intake, only the plus version was more effective than providing generic nutrition information. Although feasible, incorporating environmental-level information is time-consuming. Therefore, the basic version may be more feasible for further implementation, although inclusion of feedback on the arrangement of the home food environment and on availability and prices may be considered for fruit and, for high-educated people, for high-energy snack intake.
  
  
  BACKGROUND
  Netherlands Trial Registry NTR3396; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3396 (Archived by WebCite at http://www.webcitation.org/6VNZbdL6w).
authors.affiliation: Maastricht University, Department of Health Promotion, School for Public Health and Primary Care (CAPHRI), Maastricht, Netherlands. linda.springvloet@maastrichtuniversity.nl.
authors.forename: Linda
authors.identifier: http://orcid.org/0000-0002-6493-2179
authors.initials: L
authors.lastname: Springvloet
authors.forename: Lilian
authors.identifier: http://orcid.org/0000-0002-5160-7086
authors.initials: L
authors.lastname: Lechner
authors.forename: Hein
authors.identifier: http://orcid.org/0000-0002-3640-2517
authors.initials: H
authors.lastname: de Vries
authors.forename: Math J J M
authors.identifier: http://orcid.org/0000-0002-2229-1131
authors.initials: MJ
authors.lastname: Candel
authors.forename: Anke
authors.identifier: http://orcid.org/0000-0002-4350-5821
authors.initials: A
authors.lastname: Oenema
mesh_terms: D000328:Adult; D000368:Aged; D003194:Computer-Assisted Instruction; D004032:Diet; D002149:Energy Intake; D005246:Feedback; D005247:Feeding Behavior; D005260:Female; D006266:Health Education / Q000379:methods*; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: cognitive feedback; computer tailoring; environmental feedback; fat consumption; fruit consumption; nutrition education; self-regulation; snack consumption; vegetable consumption