That GLP-1 agonists are as successful as they are and appear to modulate the reward center of the brain (per the latest research on the same class of drugs and smoking/alcohol cessation) suggests that it's certainly not just a psychological matter.

That's why I made the heroin comparison. People underappreciate the addictive properties of refined sugars.

Edit: people also looked at the opiate angle too, apparently. https://pennstatehealthnews.org/2024/04/qa-can-weight-loss-d...