Comparing Approaches to Increasing Fruit and Vegetable Intake and Their Influence on Metabolic Health

NCT06628401 | Completed

• 2 other identifiers: 2792/48171NU-019324
• Study Type: interventional
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

This experimental study aims to evaluate the effects of different strategies for increasing fruit and vegetable intake and to see how these interventions influence markers of health in people aged 18-65 who currently consume fewer than 2 portions of fruit and vegetables a day. The main questions it aims to answer are:

• Group 1 (Control) - information on the importance of including an experimental control in research and a weekly voucher to spend at a retailer of their choice,
• Group 2 (F\&V) - information on 5-a-day advice (excluding fruit juice) and a weekly voucher to spend in a supermarket on F\&V, and
• Group 3 (F\&V + Juice) - information on 5-a-day advice (including fruit juice) and a weekly voucher to spend in a supermarket on F\&V.

Conditions

Metabolic Health; Fruit and Vegetable Intake

Outcome Measures

Primary Outcomes (1)

• Number of daily fruit and vegetable portions (from dietary recalls)

  The number of daily portions of fruit and vegetables consumed (including fruit juice in group 3) will be determined by 4 x 24-hour dietary recalls using the validated dietary recall software Intake24 (Foster et al., 2019).

  4 weeks

Secondary Outcomes (17)

• Number of daily fruit and vegetable portions (from brief screening tool)

  4 weeks

• Concentration of plasma ascorbic acid

  4 weeks

• Concentration of serum carotenoids (lutein)

  4 weeks

• Concentration of serum carotenoids (zeaxanthin)

  4 weeks

• Concentration of serum carotenoids (beta-cryptoxanthin)

  4 weeks

Study Arms (3)

Group 1 (Control)

PLACEBO COMPARATOR

Participants will be asked to maintain their habitual diet throughout the intervention. They will be provided with a brief document outlining the importance of a control group in research studies to maximise compliance. They will also receive £10/week vouchers during the intervention period and a further £60 on completion of the study to replicate voucher provision in the two intervention groups. Mimicking the voucher provision structure of the intervention groups will help to minimise participant drop out and will avoid any bias associated with differential financial remuneration between groups.

Behavioral: Educational information (Control)

Group 2 (Whole F&V)

ACTIVE COMPARATOR

Participants will be provided with educational material to increase their fruit and vegetable intake to meet 5-a-day guidelines via exclusive intake of whole fruits/vegetables . They will receive £10/week supermarket vouchers during the intervention period to support fruit/vegetable purchase. They will receive a further £60 on completion of the study.

Behavioral: Educational information (Increasing F&V intake)

Group 3 (Whole F&V + Juice)

EXPERIMENTAL

Participants will be provided with educational material to increase fruit and vegetable intake to meet 5-a-day guidelines, with recommendations to consume one portion per day via fruit juice/smoothies. Participants will receive the same financial support as group 2.

Behavioral: Educational information (Increasing F&V intake + Juice)

Interventions

Educational information (Control) BEHAVIORAL

Information packs will be developed for participants outlining the importance of a control group in research studies to maximise compliance. Participants will receive a £10 gift voucher weekly that they can spend at selected retailers of their choosing.

Group 1 (Control)

Educational information (Increasing F&V intake) BEHAVIORAL

Information packs will be developed to support participants in increasing their intake of whole fruits and vegetables, excluding fruit juice. The information packs will be developed using published guidance from the UK government, expert panels, and regulatory bodies. The packs will be co-developed with the public to ensure the guidance is appropriate for its target audience. Participants will also receive a £10 supermarket voucher weekly to purchase fruit and vegetables.

Group 2 (Whole F&V)

Educational information (Increasing F&V intake + Juice) BEHAVIORAL

Information packs will be developed to support participants in increasing their intake of whole fruits and vegetables, including fruit juice. The information packs will be developed using published guidance from the UK government, expert panels, and regulatory bodies. The packs will be co-developed with the public to ensure the guidance is appropriate for its target audience. Participants will also receive a £10 supermarket voucher weekly to purchase fruit and vegetables.

Group 3 (Whole F&V + Juice)

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 18 - 65 years
• Currently consuming ≤2 portions of fruit and vegetables per day

You may not qualify if:

• Using high-dose vitamins, minerals or dietary supplements that could interfere with biomarker assessment of fruit and vegetable consumption
• Have a food sensitivity, allergy or other dietary restriction (e.g., following a weight loss diet) that would limit the ability to take part in the study
• Have a medical condition (e.g., diabetes or gastrointestinal disorders) that would limit the ability to take part in the study
• Currently pregnant or lactating

Sponsors & Collaborators

• Courtney Neal: lead
• Newcastle University: collaborator
• European Fruit Juice Association (AIJN): collaborator

Study Sites (1)

Newcastle University

Newcastle upon Tyne, Tyne and Wear, NE2 4HH, United Kingdom

Location

Study Officials

• Oliver M Shannon, PhD

  Newcastle University

  PRINCIPAL INVESTIGATOR

• Anthony Watson, PhD

  Newcastle University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Research Assistant

Study Record Dates

• First Submitted: September 2, 2024
• First Posted: October 8, 2024
• Study Start: October 23, 2024
• Primary Completion: March 21, 2025
• Study Completion: September 5, 2025
• Last Updated: October 6, 2025

Record last verified: 2025-09

Locations

GB (1)