Optimizing an mHealth Intervention to Change Food Purchasing Behaviors for Cancer Prevention
Condition: Cancer
Study type: Interventional

Summary: 
      Dietary intake is a powerful, modifiable factor that influences cancer risk. Unfortunately,
      most adults in the U.S. find it difficult to adhere to dietary guidelines for cancer
      prevention. One promising pathway for improving dietary adherence is to target grocery
      shopping habits, i.e., foods purchased for consumption at home. Two-thirds of daily food
      intake is sourced from or eaten in the home, so improving the quality of the home food
      environment should improve overall diet quality. When healthy foods are purchased and
      unhealthy foods are not, minimal self-control is needed to make healthy eating choices in the
      home. At the point of purchase, it is difficult to resist the temptation of palatable foods,
      but interventions might facilitate healthy choices by promoting dietary goal salience in
      real-time while grocery shopping, enhancing motivation to make and sustain changes to the
      diet, and increasing household support and accountability for healthy food purchasing. The
      proposed study will enroll adults who have low adherence to cancer prevention dietary
      recommendations. All participants will attend a nutrition education workshop conducted via
      Zoom. For 20 weeks, all participants also will receive once weekly reminders and
      recommendations for food purchasing via an app. The study will experimentally test four
      additional intervention components: location-triggered messages, coaching monitoring of food
      purchases, benefit of change content, and household member involvement. The preliminary aim
      of the study is to assess feasibility and acceptability of the intervention components. The
      primary aim of the study is to quantify the effect of each intervention component,
      individually and in combination, on dietary intake (assessed with 24-hour food recalls). The
      overarching goal of this project is to optimize this mHealth intervention, which can be
      tested in the future in a fully powered clinical trial.
    


Intervention name(s): Location-triggered notification; Reflections on benefits of change; Coach monitoring; Household support
Intervention type(s): Behavioral; Behavioral; Behavioral; Behavioral
Intervention description(s): If participants are randomized to have this component ON, the app will send the notification when the participant's smartphone is within a 50-meter "geofence" around designated grocery stores. No more than one notification will be sent per week. Mindfulness of program goals in the moment of decision making is expected to facilitate program-consistent food purchasing behaviors. Participants assigned to have location-triggered message delivery OFF will receive their weekly "recommendations and reminders" messages at standard times throughout the week. The content of the messages will not differ according to whether this component is ON vs. OFF.; Participants will reflect on anticipated benefits of purchasing healthy foods, consistent with motivational interviewing and self-determination theory. Message content will be personalized as follows: During the initial workshop, all participants will complete an exercise identifying benefits of healthy eating that are important to them. Message content will then be programmed to be personalized according to anticipated rewards important to that participant. Participants assigned to have this intervention component OFF will not have content about anticipated benefits of change added to any messages.; Coaches will monitor participant food purchases via a dashboard for viewing purchase data, and send messages designed to provide feedback and enhance supportive accountability for program goals. The messages will provide reinforcement for purchases consistent with program goals and express concern for areas in which adherence is low. Participants assigned to have this component OFF will not receive these extra messages or phone calls, and their food purchases will only be viewed by research staff for research outcome assessment purposes.; If participants are assigned to have household support ON, one adult in the household will receive weekly text messages designed to elicit support for changing food purchases. In addition, the index participant and household member will be invited to participate in one extra workshop session and three brief coaching calls focused on household support. If participants are assigned to have this OFF, household members will have no program involvement.
Allocation: Randomized
Intervention model: Factorial Assignment
Intervention model description: This is a 2x2x2x2 design. There are four factors, each with two levels: ON vs OFF.
Masking: Single (Outcomes Assessor)
Primary purpose: Prevention