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Enhanced Broccoli Consumption After a Liking Norm and Vegetable Variety Message: Effects After a 24 Hour Delay.

Enhanced Broccoli Consumption After a Liking Norm and Vegetable Variety Message: Effects After a 24 Hour Delay.

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02618174
Enrollment
400
Registered
2015-12-01
Start date
2013-10-31
Completion date
2014-07-31
Last updated
2015-12-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Eating Behaviour

Brief summary

Encouraging individuals to eat vegetables is difficult. However, recent evidence suggests that using social-based information might help. For instance, it has been shown that if people think that others are eating lots of fruit and vegetables, that they will consume more of these foods to match the 'norm'. The purpose of this study was to determine whether a liking social norm (information about how much others like vegetables) would be effective at encouraging people to eat more vegetables and to examine whether these effects are sustained beyond initial exposure (i.e. whether the effect of the norm persists on food selection 24 hours alter).

Detailed description

Using a 2 x 5 x 2 experimental design we investigated the effects of exposure to various messages on later food intake and whether any effects were sustained 24 hours after exposure in both low and high consumers of vegetables. There were three factors of delay (immediate food selection versus food selection 24 hours after exposure), message type (liking norm, descriptive norm, health message, food-based control, and neutral control message) and habitual consumption (low versus high). The buffet consisted of three raw vegetables, three energy-dense foods and two dips. In this study the investigators hypothesised that a liking norm would increase the consumption of vegetables (compared to a neutral control condition) and that the effect would persist on vegetable consumption 24 hours after intital exposure to the liking norm.

Interventions

Message about age of University of Birmingham

BEHAVIORALFood-based Control Condition

Message about variety of vegetables in the world

BEHAVIORALHealth Condition

Message about the health benefits of eating vegetables

Message suggesting most people eat plenty of vegetables

BEHAVIORALLiking Social Norm

Message suggesting most people like eating vegetables

Sponsors

Economic and Social Research Council, United Kingdom
CollaboratorOTHER
University of Birmingham
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

Inclusion criteria

* Healthy volunteers * Sufficiently fluent in English

Exclusion criteria

* Smokers * Diabetes * Food allergies * Past / present depression or anxiety * Past / present eating disorder.

Design outcomes

Primary

MeasureTime frame
Grams of vegetables consumed8 months

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 2, 2026