ImpRoving hEalth behaviourS for LIfe After ENdometrial CancEr Trial

Inclusion Criteria:

* ≥ 18 years old
* Histologically confirmed endometrioid adenocarcinoma (low-grade), FIGO 2009 stages I to III.
* 1 month to 10 years post-surgery and completion of adjuvant treatment.
* Self-reported BMI ≥25 and ≤45 kg/m2, or self-reported BMI ≥18.5 and ≤24.9 kg/m2 together with a cardiometabolic condition or waist circumference ≥80 cm. Cardiometabolic conditions are also self-reported and included type 2 diabetes, prediabetes, hypertension, dyslipidemia, coronary artery disease, and stroke among others.
* Willing and able to adhere to the study interventions and assessments
* Seeking best weight using the readiness to change questionnaire.
* Have a cell phone compatible with the Fitbit app with internet access and Bluetooth capabilities.
* Able to speak, read and understand English.

Exclusion Criteria:

* Recurrent (local, regional, or distant) or metastatic EC.
* Abnormal (i.e., mutated) p53 status in combination with FIGO 2009 stage III or IV
* Weight fluctuations (±5 kg) within the previous 3 months.
* Planned surgery in the next 6 months.
* Previous bariatric surgery.
* Uncontrolled thyroid disorder
* Type 1 diabetes.
* Type 2 diabetes with HbA1c \> 10% or are taking insulin, sulfonylureas, or GLP-1 agonists.
* Taking corticosteroids.
* Taking anti-obesity drugs.
* Current smoker (of any type, e.g e-cigarettes, tobacco, marihuana, vaping)
* Self-report \>90 moderate-intensity min/week of aerobic physical activity on average over the past three months.
* Potential safety risk with exercise or maximal exercise testing screened with the 2023 Physical Activity Readiness Questionnaire (PAR-Q+)53, signs and symptoms of CVD, and any of the American Heart Association's absolute or relative contraindications to exercise testing.
* Physical or mobility limitations impacting ability to perform physical activity.
* Self-report following a structured hypocaloric diet (e.g., using formulated meal replacements, weight loss meal program) or a restrictive diet (intermittent fasting, or high-fat diet) in the past three months, or self-report currently following a vegan diet but for less than two years.
* Self-reported history of an eating disorder diagnosed by a physician.
* Intending to be away longer than 2 weeks consecutively during the intervention and unable to adhere to the study protocol during this period.
* Active substance abuse (alcohol, cannabis, illicit drugs, prescription drugs).
* Dual-energy x-ray absorptiometry (DXA) or magnetic resonance imaging (MRI) contraindications for research purposes, such as pacemakers or pregnancy
* Unable to participate in telephone and virtual intervention protocols (e.g., having a severe hearing or vision loss).
* Unable to adhere to the study protocol (i.e., unavailable to commit to scheduled group video conferencing sessions; limited access to the Internet; not willing to use platform, individuals who have been advised by a health professional not to lose weight or reduce caloric intake; cognitive impairment or dementia; etc.).
* Unable to come to study location.
* Unable to provide written informed consent.