Insulin-Mediated Glucose Uptake and Organ Perfusion Assessed by Total-Body PET During GIP and GLP-1 Infusion

Sub-study 1 (Healthy individuals): * Age 23-50 years * BMI 20.0-26.9 kg/m² * HbA1c \< 42 mmol/mol * Able to provide informed consent Sub-study 2 - Participants with Type 2 Diabetes: * Age 23-60 years * Diagnosed with type 2 diabetes for ≥3 months * HbA1c \> 53 mmol/mol * Treatment with metformin only * Able to provide informed consent Sub-study 2 - Healthy control participants: * Age 23-64 years * HbA1c \< 42 mmol/mol * Able to provide informed consent Exclusion Criteria (applies to all participants unless otherwise specified): * Anaemia (haemoglobin below normal range) * ALT \> 2× upper normal limit or any known hepatobiliary or gastrointestinal disorder * Kidney disease (creatinine above normal range) * Previous gastric or intestinal resection (except appendectomy or cholecystectomy) or major abdominal surgery (including bariatric surgery) * For Sub-study 1: Type 1 or type 2 diabetes or HbA1c ≥ 42 mmol/mol * Use of glucose-lowering medications other than metformin (Sub-study 2 only) * Chronic obstructive pulmonary disease (Sub-study 2 only) * Regular tobacco smoking or use of nicotine-containing products * Claustrophobia * Pregnancy, breastfeeding, or intention to become pregnant during the study period * Initiation of special diets, major lifestyle changes, or weight loss \> 5% within 3 months prior to or during the study * Any medication or physical/psychological condition that may interfere with participation (per investigator judgement) * Inability to speak or read Danish