This so perfectly describes the reason I don't rely on snacks. If I'm hungry, snacks just annoy me. When I eat, I want to eat to satisfaction and physical fullness, not a few bites of something and then turning on the willpower to stop.
If I find myself getting hungry at odd times, I use that information going forward to make sure I plan bigger and more satisfying meals. That way I don't end up in the same snacky predicament every day. This was a key to "reverse engineering" my meals to be the right size. I notice whether I'm getting hungry too soon or not at all before typical meal times and make adjustments for next time. Repeat, repeat, repeat, until it's so dialed in I just know and rarely over or undershoot it anymore.
When I snack these days, it's almost always for fun and not hunger. That actually makes it easier for me to stop. I can savor a few bites of whatever I'm baking, the treat my neighbor gave me, or the potato chips my husband is eating, and then easily stop because I'm not hungry now and I still want to be hungry for dinner. It's the best of both worlds. I'm not denying myself the treat and I'm still appropriately hungry for my next meal.
On the rare occasions when I do get physically hungry enough that I don't want to or can't wait, like when we're going to dinner in a restaurant in two hours and the time is set, it's easier to stop short on a snack if the focus is on fat. Some cheese and crackers, or avocado and crackers, a handful of nuts, celery with peanut butter. Something like that and I have much better luck putting on the brakes. If I'm physically hungry, dinner is in two hours, and I open a bag of potato chips or candy, or even start eating grapes or something, good luck stopping! Oh, well, it happens though. :-) I'll still enjoy dinner. I may just bring more of it home.