That’s really the center of the whole thing right there.
If you’re genuinely short of calories, eat real food. Perhaps in small quantities, but real food.
Snacking is much more a boredom relieving gambit than it is a feeding behavior. Which is why smokers who quit often turn into snackers. It’s something to fiddle with to reduce boredom and it involves their mouth. Just as cigs did.
If you’re fighting eating-as-boredom-relief (and I put all eating in front of a TV in that category), first off rename it. You’re not “snacking”; you’re “bored-eating”. Calling your enemy by his/her true name is an important part of understanding and conquering him/her. Bored-eating is a very different beast from grazing a table of snacky food at a party even if the menu is exactly the same.
Next redirect it. When the urge to bored-eat hits, indulge it. By getting yourself a 12oz glass of water, no-cal flavored water, no-cal fizzy water, or if you must no-cal soda/cola/whatever. Slowly drink that whole thing. The boredom is relieved, the urge to involve taste buds and mouth is relieved, and 12 floz is a pretty bulky snack that doesn’t quickly compress in the stomach. Pretty soon you’ll recognize that that’s actually more quantity than you actually wanted added to your stomach. But, critically, it isn’t carb-y snack food where each bite triggers more desire to eat even as it packs in the body-fattening carb-y calories.
After a month or two’s practice with this you’re ready for the last step: resist it. Once you naturally automatically think “Oh yeah, I’m not actually hungry, I’m just bored.” it becomes easy to say “I don’t really need the liquid; I just need to do something totally different to break the boredom.” Walk around, switch work tasks, quit 'Doping, whatever.
Rename, redirect, resist.
No one step is hard or large. Do one, it’ll lead you to the second in due course, which will lead you to the third in due course as well.