If you start having negative physical symptoms but keep drinking then you'd start to fall into that category. I don't know if addict is the right word but I'd say he has a higher intake than the mean.
As a milk drinker I am interested in these negative physical symptoms. Can you provide more details or link to the relevant things that you are thinking of?
Not 100% certain. I have IBS-like symptoms. Even whey protein (which has no lactose) makes my stomach rumble. Sometimes get flashes of heat from consuming dairy.
The tricky thing is, I used to eat that and other foods for years without any symptoms so severe that I should obviously eliminate them.
But, after eliminating dairy and a few other foods, my day to day digestion and energy levels are consistently higher. I've tested reintroducing them.
Relating this back to alcohol, the idea is that something could have significant effects, yet they're not high enough to be an acute problem. So you can persist in a behavior that harms you, without being addicted. You just haven't realized you might benefit from stopping.
If I started drinking milk every day, I would experience a variety of (mostly negative) physical symptoms. Doesn't mean I would be addicted to it.