Recruitment: Patients of orthopaedic surgeons (e.g. Dr. Antonia Chen, Dr. Jeffrey Lange, Dr. Vivek Shah, Dr. Richard Iorio and Dr. Wolfgang Fitz) at the Brigham and Women's Hospital or Mass General Hospital orthopaedic clinics will be identified as potentially eligible for the study based on 1) 40 \< body mass index (BMI) \< 47 kg/m2 in the last 6 months recorded in the Partners electronic medical record, and 2) recommended unilateral total joint arthroplasty. Study flyers will be posted in MGH orthopedics clinics to remind clinicians that their patients may be eligible for the study, or patients may directly contact the research team by emailing the contact person on the flyer. For patients identified as potentially eligible while in clinic, an orthopaedic surgeon will introduce the patient to the study, and a member of the research team (research assistant or trainee) will conduct an eligibility screening (see eligibility criteria above) and obtain verbal consent either in-person or by phone. For patients identified as potentially eligible outside of clinic, a member of the research team will call the patient to introduce the study, and conduct eligibility screening and consent on the phone. Research staff may also contact these patients by email or via Patient Gateway to help coordinate a time convenient for staff to call the patient.

Interested, eligible, and consented subjects will be provisionally enrolled and each subject (both intervention and standard care participants) will be shipped a standard bathroom scale that they will keep even after the study concludes. Subjects will be asked to verify their enrollment BMI is 40 \< body mass index (BMI) \< 47 kg/m2. Subjects can verify weights by either a) submitting a photo to the study team of the home scale during a weigh-in that displays their body weight, or by b) recording a baseline weight at a Partners facility. For option a) subjects will submit a photo of their weight displayed on the scale to the study team either by email to a study team member's Partners email address, through the mobile app, or via RedCap. Subjects who are not able to confirm their enrollment BMI is within this range will be removed from the study. Subjects who can confirm their enrollment BMI is within this range will then be randomized to a trial arm.

Arms: Intervention participants will download the Nutrimedy telemedicine online/smartphone app and be connected at enrollment with a certified registered dietitian who will contact intervention participants weekly or bi-weekly via video calls and unlimited in-app text messaging for up to three months. The first week will include either one 55-minute video session or two 25-minute sessions. Weeks 2-4 will have weekly 25-minute video calls, and weeks 5-12 will have biweekly 25-minute sessions for a total of 8-9 sessions over 12 weeks. Together, participants and dietitians will come up with goals for the 12 weeks, and dietitians will check on progress toward these goals using in-app tools such as food logs and messaging between video calls. All patients will be encouraged to lose at least 20 pounds with a goal BMI\<40 kg/m2 after 12 weeks. Intervention participants will additionally be asked if they would be interested in completing a brief 5-minute interview in-person or by phone at the end of the study (10-14 weeks after enrollment) to discuss qualitative feedback about the intervention. Responses will be transcribed verbatim during the interview for later analysis.

Individuals randomized to the usual care group will receive standard care. This may include a physical therapist and/or nutritionist referral. Brigham and Women's Hospital offers several programs for patients interested in losing weight, including the Nutrition Wellness Service (NWS) and Program for Weight Management (PWM).