A Research Study to See How Much CagriSema Lowers Blood Sugar and Body Weight Compared to Placebo in People With Type 2 Diabetes Treated With Diet and Exercise

Inclusion Criteria: * Male or female * Age 18 years or above at the time of signing the informed consent * Diagnosed with type 2 diabetes \>=30 days before screening * HbA1c 7.0-9.5 percent (53-80 millimoles per mole \[mmol/mol\]) (both inclusive) as determined by central laboratory at screening * Body mass index (BMI) \>=23 kilograms per square meter (kg/m\^2) at screening. BMI will be calculated in the electronic case report form (eCRF) based on height and body weight at screening Exclusion Criteria: * Female who is pregnant, breast-feeding or intends to become pregnant or is of childbearing potential and not using a highly effective contraceptive method * Renal impairment with estimated Glomerular Filtration Rate less than 30 milliliter per minute per 1.73 square meter (ml/min/1.73 m\^2) as determined by central laboratory at screening * Treatment with any medication for the indication of diabetes or obesity within 90 days before screening. However, short term insulin treatment for a maximum of 14 consecutive days and prior insulin treatment for gestational diabetes are allowed * History of use of any injectable therapy for diabetes or obesity. However, short term insulin treatment for a maximum of 14 consecutive days and prior insulin treatment for gestational diabetes are allowed * Uncontrolled and potentially unstable diabetic retinopathy or maculopathy. Verified by a fundus examination performed within 90 days before screening or in the period between screening and …