Impact of Healthy Food Subsidies on Diet Quality and Food Security

NCT06992947 | Completed

• 2 other identifiers: REB24-1774195904
• Study Type: interventional
• Target: 538
• Locations: 1 country
• Sites: 1

Brief Summary

The British Columbia Farmers' Market Nutrition Coupon Program (FMNCP) provides lower-income households with coupons to purchase healthy foods at farmers' markets. This pragmatic randomized controlled trial (RCT) will examine the effectiveness and cost-effectiveness of two higher subsidies for healthy food ($54/weeek or $81/week), compared to the usual FMNCP healthy food subsidy ($27/week), on the diet quality (primary outcome), food insecurity, and other health-related outcomes of 276 parent-child dyads with lower incomes. 276 parent-child dyads who are enrolled in the FMNCP will be randomly assigned to one of the three subsidy arms. Participants will receive 16 weeks of coupons that can be redeemed for up to 20 weeks. Outcomes will be assessed in one parent (18-64 years) and child (6-17 years) from each household pre-, mid- and post-intervention.

Conditions

Food Insecurity

Keywords

Randomized controlled trial; diet quality; food insecurity; low-income; healthy food subsidy; adults; children; parental shielding; dose-response; farmers market

Outcome Measures

Primary Outcomes (2)

• Overall Diet Quality in Parents

  Difference between intervention groups and SUBSIDY-Usual in diet quality by Healthy Eating Food Index-2019 scores in parents. Dietary intake will be collected via two 24-hour dietary recalls at each time point to calculate diet quality. Scores can range from 0-80. A higher score indicates a higher diet quality.

  Assessed pre- and post-intervention (i.e., after participants have redeemed at least 15 weeks of coupons)

• Overall Diet Quality in Children

  Difference between intervention groups and SUBSIDY-Usual in diet quality by Healthy Eating Food Index-2019 scores in children. Dietary intake will be collected via two 24-hour dietary recalls at each time point to calculate diet quality. Scores can range from 0-80. A higher score indicates a higher diet quality.

  Assessed pre- and post-intervention (i.e., after participants have redeemed at least 15 weeks of coupons)

Secondary Outcomes (23)

• Overall Diet Quality in Parents

  Assessed pre- and mid-intervention (i.e., after 8 weeks of coupons have been distributed)

• Overall Diet Quality in Children

  Assessed pre- and mid-intervention (i.e., after 8 weeks of coupons have been distributed)

• Diet Quality Component Scores in Parents

  Assessed pre-, mid- (i.e., after 8 weeks of coupons have been distributed) and post-intervention (i.e., after participants have redeemed at least 15 weeks of coupons)

• Diet Quality Component Scores in Children

  Assessed pre-, mid- (i.e., after 8 weeks of coupons have been distributed) and post-intervention (i.e., after participants have redeemed at least 15 weeks of coupons)

• Percent Energy from Ultra-Processed Foods in Parents

  Assessed pre-, mid- (i.e., after 8 weeks of coupons have been distributed) and post-intervention (i.e., after participants have redeemed at least 15 weeks of coupons)

Other Outcomes (11)

• Coupon Receipt

  Assessed bi-weekly from pre- to post-intervention (i.e., when the farmers' market a household shops at closes for the season)

• Coupon Redemption

  Assessed each time participants purchase food using FMNCP coupons from pre- to post-intervention (i.e., when the farmers' market a household shops at closes for the season)

• Nutrition Skill-Building Activity Attendance

  Assessed based on written records recorded from pre- to post-intervention (i.e., when the farmers' market a household shops at closes for the season)

Study Arms (3)

SUBSIDY-2

EXPERIMENTAL

Participants in this group will receive 16 weeks of coupons valued at $54/household/week, which is two times higher than the usual FMNCP subsidy. The subsidy will be provided in the form of coupons that can be used to purchase healthy foods at BC farmers' markets, including vegetables, fruits, dairy, meat, poultry, fish, eggs, nuts, vegetable and fruit plants, honey and herbs. Participants will also be invited to participate in nutrition skill-building activities (e.g. cooking and gardening classes) offered by community partners. Participation in these activities is optional, which is consistent with the existing FMNCP.

Other: Healthy food subsidy: $54/household/week; Other: Nutrition skill-building

SUBSIDY-3

EXPERIMENTAL

Participants in this group will receive 16 weeks of coupons valued at $81/household/week, which is three times higher than the usual FMNCP subsidy. The subsidy will be provided in the form of coupons that can be used to purchase healthy foods at BC farmers' markets, including vegetables, fruits, dairy, meat, poultry, fish, eggs, nuts, vegetable and fruit plants, honey and herbs. Participants will also be invited to participate in nutrition skill-building activities (e.g. cooking and gardening classes) offered by community partners. Participation in these activities is optional, which is consistent with the existing FMNCP.

Other: Healthy food subsidy: $81/household/week; Other: Nutrition skill-building

SUBSIDY-Usual

ACTIVE COMPARATOR

Participants in this group will receive 16 weeks of coupons valued at $27/household/week, which is the usual FMNCP subsidy. The subsidy will be provided in the form of coupons that can be used to purchase healthy foods at BC farmers' markets, including vegetables, fruits, dairy, meat, poultry, fish, eggs, nuts, vegetable and fruit plants, honey and herbs. Participants will also be invited to participate in nutrition skill-building activities (e.g. cooking and gardening classes) offered by community partners. Participation in these activities is optional, which is consistent with the existing FMNCP.

Other: Healthy food subsidy: $27/household/week; Other: Nutrition skill-building

Interventions

Healthy food subsidy: $54/household/week OTHER

Participants receive 16 weeks of coupons valued at $54/week to purchase healthy foods at BC farmers' markets. Eligible foods include vegetables, fruits, dairy, meat, poultry, fish, eggs, nuts, vegetable and fruit plants, honey and herbs.

SUBSIDY-2

Healthy food subsidy: $81/household/week OTHER

Participants receive 16 weeks of coupons valued at $81/week to purchase healthy foods at BC farmers' markets. Eligible foods include vegetables, fruits, dairy, meat, poultry, fish, eggs, nuts, vegetable and fruit plants, honey and herbs.

SUBSIDY-3

Healthy food subsidy: $27/household/week OTHER

Participants receive 16 weeks of coupons valued at $27/week to purchase healthy foods at BC farmers' markets. Eligible foods include vegetables, fruits, dairy, meat, poultry, fish, eggs, nuts, vegetable and fruit plants, honey and herbs.

SUBSIDY-Usual

Nutrition skill-building OTHER

Participants are eligible, but not required, to attend optional nutrition skill-building activities (e.g. cooking and gardening classes).

SUBSIDY-2; SUBSIDY-3; SUBSIDY-Usual

Eligibility Criteria

• Age: 6 Years - 64 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Meet existing FMNCP-specific annual household income eligibility cut-offs that account for the local cost of living
• Have 2-5 members in the household, specifically with a parent 18-64 years and a child 6-17 years. If there are multiple eligible individuals, the parent who is the primary food shopper and the youngest child will be enrolled.
• Parent-child dyads must reside together ≥5 days/week
• Are the only dyad in their household participating in the study
• Have access to the internet and a camera
• Able to communicate in English or have someone to translate

You may not qualify if:

• Trying to conceive, pregnant or breastfeeding
• Participating in other trials that might interfere with the intervention
• Reside in a facility that provides meals (e.g., shelter, long-term care) or where they cannot prepare meals (e.g., hotel)
• Anticipate being outside of their community for \>2 consecutive weeks during the study
• Expect to move to a non-FMNCP community during the study
• Expect a significant change in their household income or composition during the study

Sponsors & Collaborators

• University of Calgary: lead
• Canadian Institutes of Health Research (CIHR): collaborator
• British Columbia Farmers' Market Nutrition Coupon Program: collaborator
• BC Association of Farmers' Markets: collaborator

Study Sites (1)

Participants recruited in 93 communities across British Columbia, Canada

Communities Across BC, British Columbia, Canada

Location

Related Links

• BC Farmers' Market Nutrition Coupon Program

Study Officials

• Dana Lee Olstad, PhD, RD

  University of Calgary

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Participants cannot be blinded to group assignment but will be blinded to the study objectives. Community partners who distribute coupons and vendors who redeem coupons at farmers' markets will be blinded to group assignment. Researchers who collect and analyze the data will not be involved in delivering the intervention and thus will remain blinded
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: May 9, 2025
• First Posted: May 28, 2025
• Study Start: June 7, 2025
• Primary Completion: December 16, 2025
• Study Completion: December 16, 2025
• Last Updated: December 31, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: August 2026 - August 2031
• Access Criteria: Data will be available from the authors upon reasonable request.

Locations

CA (1)