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

A Comparison Between Different Approaches to Increase Fruit and Vegetable Intake and Influence Markers of Metabolic Health in Humans

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:

1. How does 5-a-day advice, with and without the inclusion of fruit juice, impact fruit and vegetable intake over a four-week period?
2. What are the acceptability and perceived ease of increasing fruit and vegetable intake with and without the inclusion of fruit juice in 5-a-day recommendations?
3. What are the effects of increasing fruit and vegetable intake with and without fruit juice on markers of metabolic health?

Researchers will answer these questions by comparing results from three groups of participants. All participants will provide a pre- and post-intervention blood sample, complete various questionnaires, and follow a four-week intervention that comprises educational material and a weekly £10 voucher. Over the course of the four weeks, they will report what they ate in a day on four different days.

The groups differ in the educational materials provided and where they can spend their voucher:

• 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.

Inclusion Criteria:

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

Exclusion Criteria:

• 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