I know it because I've seen it.
The snack situation at our house used to look something like this:
Mom goes to the store on Friday and buys: a couple of boxes of granola bars, some cookies, some salty snack mix, and maybe some nuts. She also buys some fresh fruit, yogurt, and snack cheese. It varies from week to week. Mom comes home from the store, puts the "Snacks" in the snack pantry. Mom blinks and the snacks are gone. For the rest of the week the kids whine because there are no snacks in the house. Meanwhile the fresh fruit rots and the yogurt expires.
THEN, Mom started couponing. She started bringing home snacks in mass quantities. Instead of two boxes of granola bars, she brings home 8 boxes. She makes two or three trips to the store to acquire it in these quantities, but the children and the teenager grin. And they descend on the snacks and devour them. In three or four days, they are whining again. Meanwhile the fresh fruit rots and the yogurt expires.
NOW, Mom got smart. I tend to blog about my new ideas right after I implement them. And as ideas usually go, some work, some don't. So it's always a little embarrassing when I brag about a new idea or plan and then a few weeks later get asked, "How's that working out?" Well, I can tell you with complete honesty that this one is working! I've been doing this for about 2 months now and it's working like a charm!
I purchase a variety of snacks ~ Salty, sweet, crunch, soft. The kids are allowed to choose SEVEN items to put in their weekly baskets.
They also have some (homemade) baskets in the fridge with some dairy choices.
And I still provide the fresh fruit ~ With no limits.
Why does it work?
Once their baskets are filled, I put the remaining snacks away ~ out of reach and out of sight.
They've begun self-budgeting their snack foods and limiting themselves to one per day from their baskets. (It didn't take long for them to figure out that if they ate from their snack basket more than once a day, they would not have anything at the end of the week.) The rest of the day they choose the dairy & the fruit for their snack choices.
My hubby gets his own snack basket too, although he's free to fill it as he sees fit. He's not a big snacker though, so it's not a problem for him.