Of course they're not exactly like food. They are powerful substances that deserve respect and you can't just "eat" them when you are "hungry" like you can with normal food. But I believe they're like food in the way that you deserve bodily autonomy wrt taking them.
Fun fact: Did you know hunger is basically just carbohydrate withdrawal? If you stop eating carbs for around 1-2 days, your hunger will go away. Obviously, if you want to stay that way, you will have to find some way to sustain yourself without carbs, but it's a relatively safe experiment to fast for a few days and see what happens.
It's fun to think of food in that way because actually... food is just a pile of substances! Carbs, fats and proteins.
It's just that food is generally safe to eat when you're hungry, but drugs are especially powerful substances that can be dangerous if misused. But still stuff that you can put into your body, through basically the exact same mechanisms as food.
I'm all for caution and research and responsibility and informed consent and all that—all good things. But I don't think drugs are inherently so much different than food that you don't deserve some level of autonomy with them.
In other words, I think the amphetamines and stuff should be OTC. Like... legalize them all, legalize everything. Not only would this make the supply safer for people who are already taking those substances, since they can be made by reputable, professional companies, but this would help get rid of the taboo around sharing safe dosage and supplement information, which would seriously help a lot of people (harm reduction!).
All the FUD around the war on drugs is just causing harm to the world. It's causing people to go to jail just from putting things into their own body, it's denying people access to safe medical information, it's barring medical professionals from helping people with substances that happen to be illegal, it's denying people a safe supply of their favorite drugs (which usually results in people going to shady sources, not abstaining completely), ... the list goes on.
Yeah, amphetamines aren't food, but it's nice to imagine a world where they're available freely and used responsibly. Unfortunately I'm not sure if that's a possible future.