Testing Counseling and Mobile Health Interventions to Improve Physical Activity and Diet Quality in Survivors of Childhood Cancer

Inclusion Criteria: * Childhood Cancer Survivor Study (CCSS) participant who is between age 18 to \< 55 years at time of initial approach * Moderate to high CV risk status based on CCSS risk prediction models for cardiomyopathy and ischemic heart disease * Able to read, write, and speak English * Ability to understand and the willingness to provide informed consent * At least one of the following: * Less than 30 minutes/day of moderate to vigorous physical activity (MVPA) based on validated self-report instrument (Godin) * Healthy Eating Index (HEI)-2015 score \< 60 per study food frequency questionnaire (FFQ) * Body mass index (BMI) \>= 25 kg/m\^2 per self-reported height and weight * Be free of any known (self-reported) ischemic heart disease or cardiomyopathy * Have internet access (can be via smartphone or computer; if neither device is available, the study can loan participants a Wi-Fi enabled device, but participant will need to have access to the internet) Exclusion Criteria: * Individuals with known cardiomyopathy or ischemic heart disease based on prior CCSS surveys are excluded. While not likely to be common, participants who newly report in our study's screening questionnaire that they have newly diagnosed cardiomyopathy or ischemic heart disease will also be excluded * Having any self-reported contraindication to walking or being physically active * Not currently known to be pregnant; individuals known to be pregnant and otherwise eligible for the study can be enrolled once no longer known to be pregnant. Participants who report being pregnant after randomization can remain in the study * Individuals receiving active cancer treatment. Participants who report starting active cancer treatment after randomization can remain in the study