As simple as that.
But no. The politics people put onto fatness complicates "no", unnecessarily- in ways that are as psychologically draining as they are boring as hell.
I'm one of those strange people who actually has some (basic) grasp of what addiction really is. I was lost in waffling as usual, 'til the other day when I had a sudden light bulb moment. I realised that the key to explaining addiction might not be pleasure (the cause of my waffling) but intoxication, d'oh!
Intoxication is the cornerstone of addiction.
For now, forget everything about that term (work with me) but the third definition;
Poisoning by a drug or toxic substanceThe point about ingesting these chemicals is they can poison you. Your body has ways of trying to prevent that from happening. Opiates, like heroin especially can relax your muscles to the point of paralysis-including such as your heart for instance- so your functioning literally comes to a halt. Our bodies naturally produce opiate like substances, in order to aid our functioning. For example to stop the working of your body from hurting. i.e. heart beat, lungs inhaling and exhaling, even joints and muscles contracting and stretching.
Your body has inbuilt protection against a potentially lethal intake of opiates, chiefly, to reduce its own production of said chemicals (obviously not infallible, but its doing what it can.)
I'm pretty sure this is the basis of some forms of chronic pain syndrome, where people are in permanent pain, but doctors can find no specific injury or reason why.
So, an intake of opiates leads to a reduction in the amount of those pleasure chemicals generated. This is what addicts speak of when they talk about how great the first time is and how its never as great again. That first time is either before the body reads and starts to react efficiently to what's going on. Once all this is experienced, it's quicker off the mark next time. This is what users call the/a"downer."
After the drugs ingested are processed by the body and the effect wears off, production can adjust back up to normal, or thereabouts.
When drug use becomes a regular enough pattern, that ability to restore normality is what can become compromised. It can wear out and function at so low a level that the person can no longer function properly without that intake. The internal production is no longer adequate.
This atrophy of function is the physiological basis of addiction.
It varies in people according to susceptibility. Genuine physiological addiction, that is when the body finds it hard or even cannot seem to recover its function to a tolerable level, is quite rare amongst drug users.
What less rare is what is really a form of emotional dependence. When factors other than physiological dependence weld people to drug use. That can be more powerful than chemical dependence.