FAMily-centered WEight Loss for Black Adults (FAM WEL B-ing)

The goal of this clinical trial is to learn the best combination of family components that yields optimal weight loss among Black adults. The main question it aims to answer is:

What combination of four family components in combination with a standard behavioral weight loss program yields optimal weight loss among Black adults? Researchers will compare different combinations of family skills components (communication content, cohesion content, number of sessions, and mode of delivery) to see the best weight loss.

Participants will:

* Participate in a 6-month behavioral weight loss intervention
* Attend core weight loss in-person group sessions, and dyad based family sessions
* Keep track of weight, dietary intake and physical activity

This clinical trial aims to determine the most effective combination of family components to achieve optimal weight loss among Black adults. The main focus is to assess how different combinations of four family skills components-communication content, cohesion content, number of sessions, and mode of delivery-work together with a standard behavioral weight loss program.

Participants will engage in a 6-month behavioral weight loss intervention, which includes attending group weight loss sessions and family-based dyad sessions. They will also track their weight, dietary intake, and physical activity.

This is a 2 x4 factorial design with 16 study conditions.

Eligibility Criteria:
Inclusion Criteria:

* self-identified as Black or African American (Index participant)
* BMI equal to greater than 30 kg/m\^2 (Index); BMI equal to greater than 27.5 kg/m\^2 (family partner)
* have a partner/family member willing to enroll in the study and must share a mutual goal of achieving weight loss
* English speaking
* ages 18-75
* any gender
* have access to and be able to use a smartphone, tablet, or computer that has web-access (this is required for data collection and some program components being tested)

Exclusion Criteria:

* participation in an intensive weight loss program (more than 12 visits) in the prior 6 months
* type 1 diabetes
* significant psychiatric illness, defined as depression or other major psychiatric illness not considered reasonably managed by counseling, medication, or both
* prior bariatric surgery or considering bariatric surgery in the next 6 months using or - - planning to start medications intentionally for weight loss
* pregnancy/breastfeeding or intended pregnancy in the next 6 months
* alcohol or substance abuse, defined as alcohol or substance use that interferes with work activities and/or has had a major negative impact on family/social function, the latter defined as more than 2 episodes per month.
* malignancy other than non-melanoma skin cancer, unless considered cured \> 5 years ago. Exceptions include 1) men with localized prostate cancer (treated with usual modalities or managed with "active surveillance"), and 2) postmenopausal women receiving adjuvant endocrine therapy (e.g., aromatase inhibitor) for non-metastatic, hormone receptor-positive breast cancer
* self-report of advanced kidney disease (estimated glomerular filtration rate (GFR) \< 30 mL/min)