JMIR Publications

ABSTRACT

Background:

Dietary intake is a powerful, modifiable factor that influences cancer risk, yet most U.S. adults do not adhere to dietary guidelines for cancer prevention. One promising pathway for improving dietary adherence is to target grocery shopping habits. Interventions might facilitate healthy grocery choices, with a combination of mHealth and traditional methods, by a) promoting salience of dietary goals while shopping, b) enhancing motivation to make dietary changes, and c) increasing household support for healthy food purchasing.

Objective:

This pilot study will assess feasibility and acceptability of intervention components designed to improve adherence to dietary guidelines for cancer prevention (preliminary aim). The primary aim of the study is to quantify the effect of each intervention component, individually and in combination, on dietary intake (primary aim) and grocery store food purchases (exploratory aim). Mediation analyses will be conducted to understand mechanisms of action (goal salience, motivation, household support; secondary aim). The overarching goal is to optimize an mHealth intervention to be tested in a future, fully powered clinical trial.

Methods:

The study enrolled adults (N = 62) with low adherence to cancer prevention dietary recommendations. In a 20-week program, all participants are attending a nutrition education workshop and receive weekly educational messages in an app. A factorial design is utilized to test four intervention components: 1) Location-triggered messages: Educational messages are delivered when arriving at grocery stores; 2) Reflections on the benefits of change: Content is added to messages to encourage reflection on anticipated benefits of healthy eating, and participants attend an additional workshop session and three coach calls on this topic; 3) Coach monitoring: Food purchases are monitored digitally by a coach who sends personalized weekly app messages and conducts three coaching calls that focus on feedback about purchases; 4) Household support: Another adult in the household receives messages designed to elicit support for healthy food purchasing, and support is addressed in three coach calls and one extra workshop session attended by the index participant and household member. Assessments are completed at weeks 0, 10, and 20 using self-report measures, as well as objective capture of grocery data from the point of purchase using store loyalty accounts.

Results:

The National Cancer Institute funded this project (R21CA252933) on July 7, 2020. Participant recruitment began in Spring 2021 and concluded with successful enrollment of 62 participants. Data collection is expected to be completed in Summer 2022 and results disseminated in Summer 2023.

Conclusions:

The results of this study will inform the development of scalable interventions to lower cancer risk via change in dietary intake. Clinical Trial: ClinicalTrials.gov NCT04947150; https://clinicaltrials.gov/ct2/show/NCT04947150