Inclusion Criteria:
* BMI 30-37 kg/m2 or BMI 27-\<30 kg/m2 with at least 1 weight-related comorbidity
* community dwelling
* able to provide own transportation to study visits
* willing to provide informed consent
* willing to take terzepatide for 9 months
* agree to all study procedures/assessments
* approved for participation by the study physician
Exclusion Criteria:
* dependent on a cane or walker or needing assistance with any activity of daily living
* history of mild cognitive impairment or dementia or cognitive impairment on Montreal Cognitive Assessment (MoCA score \<22)
* evidence of depressive symptoms (Center for Epidemiologic Studies Depression scale score =\>16
* use of \>1 tobacco product/day or 4/week or vaped \>1/week in past year
* excessive alcohol use in past month (\>7 drinks/week for women; \>14 drinks/week for men)
* weight loss or gain \>5% in past 3 months
* vegan or other severe dietary restriction
* history of binge eating disorder
* regular participation in high intensity aerobic or resistance exercise training \>150 mins/week
* severe arthritis, fracture, chronic injury, or other musculoskeletal disorder that prevents walking independently
* joint replacement or other orthopedic surgery in past 6 months or planned in next 12 months
* osteoporosis (self report or DXA t-score \<= -2.5 on total hip and/or femoral neck)
* uncontrolled hypertension (systolic \>160 OR diastolic \>100 mmHg) upon repeated assessments
* type 1 diabetes
* uncontrolled type 2 diabetes (HbA1c \>7.5%), type 2 diabetes diagnosed within last year, or newly identified type 2 diabetes (HbA1c \>6.5%)
* dialysis or abnormal kidney function (eGFR \<30 ml/min/1.73m2)
* liver disease or abnormal liver function (ALT levels 2 times above normal limit)
* severe anemia (Hb \<11 g/dL)
* potassium or sodium above or below normal limits
* uncontrolled thyroid disease (hypo/hyper) or requiring recent (past 3 months) adjustments in thyroid hormone supplementation or TSH \<0.45 or \>4.5 mU/L
* stroke, heart attack, heart failure hospitalization, or revascularization procedure within the past year; New York heart failure Class \>2; COPD requiring oxygen use; uncontrolled angina; PAD diagnosis within the last year; progressive neurologic disease (e.g., Parkinson's, ALS, MS); other diseases suggesting a life-expectancy \<3 years
* personal or family history of medullary thyroid carcinoma, history of multiple endocrine neoplasia syndrome type 2, or any other cancer (except non-melanoma skin cancers) requiring treatment in past year
* history of gastroparesis or pancreatitis
* cholelithiasis, severe irritable bowel syndrome or Crohn's disease
* history of stomach or small intestinal surgery (except appendectomy but including surgery for weight loss)
* recent (within 4 weeks) acute respiratory illness including influenza, COVID-19
* overnight hospitalization within the past 6 months
* regular use of growth hormones, medications prescribed for weight management, prescription osteoporosis medications, certain prescription medications for diabetes including insulin, sulfonylurea, meglitinides, GLP-1 agonists, SGLT2 inhibitors
* use of oral steroids for \>1 month within the last 3 months
* current participation in another intervention research study
* planned out of town trips greater than 3 weeks in the next year
