I understand your problem. I usually see things with mathematical logic.
I use these two techniques: tell and enlist others, like you said, or replacement.
For example, I took a package of sugar home from the restaurant and measured it. One can of Coke contained 24 packs! I quit immediately and lost 25 pounds. I also removed all sugar snacks from the house, but added one — the replacement.
I love warm, chocolate chip cookies, straight out of the oven. One brand came as individually frozen, unbaked cookies. I selected one cookie, waited the 15 minutes for it to bake, then ate it. If I wanted another one, I had to wait another 15 minutes. USUALLY, one was enough.
If I had baked 15 cookies, I would have eaten all 15 cookies.
It’s important to know yourself.