Dose-escalation and Food Effect Study of ZT006 in Healthy, Overweight and Obese Participants

Inclusion Criteria: * Considered to be generally healthy based on the medical history, physical examination, and the results of vital signs, 12-lead electrocardiogram and clinical laboratory tests (hematology, urinalysis, chemistry, coagulation), as judged by the investigator. * Male or female, age between 18 - 55 years (both inclusive) at the time of signing of the informed consent. * Body mass index (BMI) 19.0 - 35.0 kg/m²(both inclusive). Body weight \>50.0 kg for male participants and \>45.0 kg for female participants. BMI 19 - 28.0 kg/m²(both inclusive) for single-dose escalation study, BMI 19.0 - 28.0 kg/m²(both inclusive) for cohorts 1 and 2 of multiple-dose escalation study, BMI 24.0 - 35.0 kg/m²(both inclusive) for cohorts 3 and 4 of multiple-dose escalation study. * Having dietary caloric restriction and increased physical activity for ≥3 months, with change in body weight (increase or decrease) no more than 5%, irrespective of medical records. Exclusion Criteria: * Known hypersensitivity to the study drug or excipients or GLP-1 receptor agonists. * Medical history of hypoglycemia. * History or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2, or history of pancreatitis or symptomatic gallbladder disease. * Previous diagnosis of endocrine disorders or monogenic mutations causing obesity, including but not limited to hypothalamic obesity, pituitary obesity, hypothyroidism-induced obesity, Cushing's syndrome, insulinoma, acromegaly, or hypogonadism. * Use of GLP-1 receptor agonists within 30 days or 5 half-lives (whichever is longer) before the first dose of the investigational intervention. * Glycated hemoglobin (HbA1c) \> 6.0% or fasting plasma glucose \< 3.9 mmol/L or \> 6.1 mmol/L at screening, or diagnosed with diabetes mellitus of type 1 or type 2 diabetes or other specific types derived from other causes. * Aspartate aminotransferase ≥ 2 × upper limit of normal (ULN), Alanine aminotransferase ≥ 2 × ULN, or total bilirubin ≥ 1.5 × ULN * Calcitonin above ULN at screening. * Other clinically significant diseases detected within 12 months before screening (including but not limited to gastrointestinal, renal, hepatic, neurological, hematological, endocrine, oncological, pulmonary, immunological, psychiatric, or cardiovascular diseases). * Use of prescription drugs (excluding topical eye/nose drops and creams without systemic exposure risk), over-the-counter drugs, dietary supplements, vitamins, or herbal medicines (excluding routine vitamins) within 2 weeks before screening. * Long-term use of medications directly affecting gastrointestinal motility prior to screening. Use of weight-loss medications (including but not limited to orlistat) within 3 months before dosing.