Eatwell Clinical Trial (R01)

The purpose of this study is to test an intervention that is designed to facilitate adherence to the dietary guidelines for cancer prevention (i.e., increase in intake of fruits, vegetables, and whole grains, and decrease in intake of processed food, red and processed meat, and sugar sweetened beverages). Using a two-arm design, participants will be randomized to receive the "Eatwell" intervention or traditional nutrition education. The Eatwell intervention content is focused on helping participants make healthier grocery shopping decisions, eat at home more often to take advantage of the optimal defaults present there, and learn how to navigate temptation when eating away from home.

Aim 1: Test the hypothesis that there will be a greater increase in adherence to dietary guidelines for cancer prevention among index participants in the Eatwell condition, compared to the traditional nutrition condition. The primary outcome will be a total dietary adherence score, calculated using NCI's standardized scoring system. Grams per day of fruit, vegetables, and fiber; percentage of calorie intake from ultra-processed foods; grams per week of red meat and processed meat; and grams per day of SSBs will be examined individually as secondary outcomes.

Aim 2: Test the hypothesis that there will be greater improvements in biomarkers of inflammation among index participants in the Eatwell condition, compared to the traditional nutrition condition.

Aim 3: Test the hypothesis that adult household members will have greater improvements in dietary adherence (measured by total dietary adherence score, as well as change in individual components of dietary quality, as in Aim 1) when their index participant is randomized to the Eatwell condition, compared to the traditional nutrition condition.

Aim 4: Examine biopsychosocial mediators and moderators of intervention effects.

Aim 5: Exploratory analyses also will be conducted to, for example, examine change over time in the variables assessed as part of the study's assessment battery, understand predictors of change over time, and understand how independent or dependent variables are related to each other.

Inclusion criteria

• Age 18 or older
• Access to technology necessary to receive emails and join videoconferencing meetings
• Ability to read and speak English
• Willingness to be randomized to either study condition, including ability and willingness to attend intervention sessions
• Ability and willingness to attend intervention sessions, receive monthly email messages, and serve in support role if index participant in household is assigned to Eatwell condition
• Able and willing to visit a commercial laboratory partnered with this project (e.g., Labcorp) in order to have their blood drawn at the time of study visits
• Low adherence to WCRF/AICR's four dietary guidelines (operationalized as a level of intake, based on brief self-report questions administered during phone screening, that corresponds to a score of 2 or less in the Shams-White method of dietary adherence scoring)
• Share a household (i.e., a private residence with a shared living space, including kitchen) with an adult who provides informed consent, meets eligibility criteria, and anticipates remaining in this household for the majority of the next 18 months
• Agree that they will not join another intervention study run by this study team in the next 18 months
• Successful completion by self and household member of all enrollment and baseline data collection tasks
• Have an email that they regularly check and willingness to use that for corresponding to study staff
• Weight at baseline of 396 lbs or less, as the digital scales used for measurement are not able to obtain measurements for weights higher than this

Exclusion criteria

• A medical or psychiatric condition, including self-reported history of anorexia nervosa or bulimia nervosa, that may limit appropriateness of or ability to comply with dietary recommendations
• A psychiatric condition, including self-reported history of anorexia nervosa or bulimia nervosa, that may make it difficult or inappropriate for household member to serve in support role
• Currently taking medication that can substantively change appetite or eating behavior, including using of a GLP-1 medication
• Planning to enroll in another lifestyle modification program in the next 18 months
• History of bariatric surgery
• Currently pregnant or planning to become pregnant in the next 18 months
• Type 1 Diabetes