Effect of LY3437943 Versus Placebo in Participants Who Have Obesity or Are Overweight

Inclusion Criteria: * Age 18 to 75 years (inclusive) at time of informed consent. * BMI ≥30 and ≤50 kg/m², OR BMI ≥27 and \<30 kg/m² with at least 1 weight-related comorbidity (hypertension; dyslipidemia; or cardiovascular disease such as ischemic CVD or NYHA Class I-II heart failure). * Motivated and able/willing to self-inject (or have trained assistance if needed) and follow study procedures, including lifestyle advice and questionnaires. * Subgroup (NAFLD addendum): liver fat content ≥10% by MRI-PDFF (for participants invited to the addendum). * Male and/or female; contraception requirements apply; women of childbearing potential must have negative pregnancy tests at specified visits and should not be breastfeeding. * Capable of giving signed informed consent and complying with protocol requirements. Exclusion Criteria: * History of diabetes mellitus (type 1 or type 2), ketoacidosis, or hyperosmolar state/coma. * Screening lab values suggestive of diabetes (HbA1c ≥6.5%; fasting glucose ≥126 mg/dL; or random glucose ≥200 mg/dL). * Self-reported change in body weight \>5 kg within 3 months prior to screening. * Prior or planned surgical treatment for obesity (exceptions: liposuction/abdominoplasty \>1 year prior). * Current/planned endoscopic or device-based obesity therapy, or device removal within last 6 months (e.g., intragastric balloon, gastric artery embolization). * Renal impairment: eGFR \<45 mL/min/1.73 m² (CKD-EPI) at screening. * Clinically significant gastric…