We will tailor a telehealth obesity intervention for obese patients with MS (figure 2). Half of the patients will be randomly assigned to 24 weekly hour-long group weight loss sessions and 6 monthly individual sessions; half will be assigned to a brief education/Treatment as Usual (TAU) control condition. Participants assigned to the control condition will also receive the active treatment 6 months following their enrollment. As such, we will have feasibility, acceptability, and outcome data for all patients who enroll and complete the intervention. During outpatient recruitment, clinicians will ask obese patients (WHtR >.57, BMI >29) if they would be willing to be contacted about a study investigating a weight loss intervention for patients with MS. Patients who express interest and respond to advertisements will be screened by telephone and via review of medical records. Patients who meet initial eligibility criteria will be invited for a baseline evaluation where they will be formally consented, complete questionnaires and behavioral tasks, and undergo a standardized physical exam. They will be monitored using actigraphy for 10 days. They will then be randomized to the group telehealth obesity intervention or TAU. At 6 months, all participants will undergo a second in-person follow-up assessment and TAU participants will begin the telehealth intervention. At 12 months, participants will undergo a third in-person assessment, providing treatment outcome data for all study participants and long-term weight maintenance data for patients initially assigned to the telehealth obesity intervention. At 18 months, participants initially assigned to the TAU control condition will undergo a 4th assessment, providing weight maintenance data for all enrolled participants.

Inclusion Criteria:

(a) a diagnosis of relapsing-remitting, secondary progressive, or primary progressive MS based on established guidelines and verified by medical chart review (b) between the ages of 18-70 (c) access to a telephone (d) English-speaking (e) ability to walk 25 feet without assistance and no severe sensory or motor impairment that would limit participation or present serious medical risks (f) no medically confirmed relapse in the past month (g) no history of dementia or severe cognitive difficulties that would limit participation (h) WHtR >.57 or BMI >29 (i) no history of bariatric surgery (j) no history of food allergies or need for a special diet preventing consumption of the recommended diet (k) no concurrent ongoing behavioral or pharmacological weight loss interventions (l) no history of insulin dependent diabetes or serious pulmonary/cardiac conditions (m) weight stability with no history of >10 pounds weight loss or gain in the 3 months prior to study participation (n) no planned or recent joint replacement surgeries (o) no serious psychiatric disorder (e.g. schizophrenia), current suicidal ideation, or current binge eating disorder as these patients may not be good candidates for behavioral weight loss programs (p) no current medical conditions where weight loss is contraindicated, as indicated by the participant's primary care physician (q) no contraindications to exercise (answer "no" to all 7 questions on Physical Activity Readiness Questionnaire; PAR-Q114) or physician approval to exercise if answer "yes" to 1 or more questions on PAR-Q. -