A Study of How CagriSema Works on Appetite in People With Excess Body Weight

Part A: The study will look at participants appetite and energy intake and also look at the mechanisms of brain associated with appetite and food intake. Participants will not get any medicine and will be in a group that will be compared to another group receiving a weight-loss medicine. The study will last for about 6 months. Part B: The study will look at how CagriSema works on participants appetite and energy intake and will be compared with a ''dummy'' medicine. The study will also look at how participants brain works when participants take the medicine. Participants will either get CagriSema or ''dummy'' medicine.