Long-term efficacy of a Web-based computer-tailored nutrition education intervention for adults including cognitive and environmental feedback: a randomized controlled trial

Abstract

BackgroundUnhealthy diets are prevalent in Western countries, especially among low-educated people. To have an effect on health, it is important that dietary changes are sustained over time. This study examines long-term effects of a cognitive and environmental-feedback version of a Web-based computer-tailored (CT) nutrition education intervention targeting fruit, vegetables, high-energy snacks and saturated fat.MethodsA randomized controlled trial was conducted with a basic (tailored intervention targeting individual cognitions and self-regulation processes; n = 456), plus (additionally targeting environmental-level factors; n = 459) and control group (generic nutrition information; n = 434). Participants were recruited from the general population and randomly assigned to a study group. Online self-reported questionnaires assessed fruit, vegetable, high-energy snack and saturated fat intake, self-regulation, self-control, and Body Mass Index (BMI) at baseline and nine-months post-intervention. Linear mixed model analyses examined group differences in change over time. Educational differences were examined by ‘group X time X education’ interaction terms. Effects were examined in the total sample and among participants who did not comply with dietary- or BMI guidelines.ResultsThe effects on vegetable intake in the total sample differed according to educational level (p = 02). Among low/moderate-educated participants, the basic version was significantly more effective in increasing vegetable intake than the control program (effect size (ES) = 0.32) and plus version (ES = 0.22). No effects were found for high-educated participants. Self-regulation change was significantly larger in the control group than in the basic (ES = 0.18) and plus (ES = 0.16) group.ConclusionsIn general, both intervention versions did not result in long-term intervention effects. The exception was an effect of the basic version on self-reported vegetable intake among low/moderate-educated adults in the total sample. More research is needed on how targeting self-regulation processes and environmental-level factors in Web-based CT nutrition education interventions can increase long-term efficacy.Trial registrationNetherlands Trial Registry NTR3396.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-1707-4) contains supplementary material, which is available to authorized users.

Lifestyle-related effects of the web-based Kanker Nazorg Wijzer (Cancer Aftercare Guide) intervention for cancer survivors: a randomized controlled trial

“…The effect size for changes in vegetable consumption ( d = 0.37) in the present study was in line with the effect size of a Dutch web-based, CT, diet-only education intervention for adults in the general population ( d = 0.32) [ 90 ]. Also, Goode et al [ 55 ] reported comparable effect sizes ( d = 0.16 to d = 1.71) for non-face-to-face interventions on fruit and vegetable outcomes.…”

Effectiveness of information technology–enabled ‘SMART Eating’ health promotion intervention: A cluster randomized controlled trial

“…In contrast, a lifestyle intervention in Sweden using counseling, group discussions on healthy eating by health workers and cooking classes by a chef to increase fruit and vegetable intake and to reduce fat intake, could not produce a significant change in behaviour outcomes [49]. Similarly, a 9-months web-based computer-tailored intervention aimed at increasing fruit and vegetable intake and decreasing saturated fat intake, did not result in significant intervention effects among Netherland adults [50]. Compared to the present study, interventions on reducing fat and sugar intake demonstrated higher effect on weight reduction [13,51].…”

Systematic review and meta-analysis of remotely delivered interventions using self-monitoring or tailored feedback to change dietary behavior

“…All studies were performed in high-income countries, with the majority ( n = 11) held in the United States ( 23 , 25 , 26 , 29 – 33 , 37 , 38 , 40 ), followed by the Netherlands ( n = 5) ( 27 , 28 , 36 , 39 , 42 , 43 ), with the rest comprised of Australia, the United Kingdom, Italy, France, and a single trial conducted in multiple European countries. There were 21,262 participants in total.…”

“…Where the information was provided, ages ranged from 18 to 79 y with the average number of participants at baseline being 818 (median 517), dropping to 598 (median 456) at study completion. Participants were found from: the general population in 6 studies ( 25 , 28 , 35 , 36 , 42 , 43 , 49 ); those with risk factors such as obesity or diabetics ( n = 4) ( 38 , 45 – 47 ); employees ( n = 5) ( 24 , 27 , 39 , 41 ); recruited from healthcare networks, e.g., primary care patients ( n = 4) ( 23 , 29 , 33 , 37 ); those with low income ( n = 3) ( 26 , 30 , 31 ); and the 4 remaining used students ( 40 , 48 ), internet shoppers ( 34 ), and those who wished to improve their diet ( 44 ).…”