I found this idea in Family Fun's last issue. This is a great magazine full of wonderful craft and travel ideas and I have gotten it for years. However, you can also access most of their ideas for free on the web.
Anyway, I was struggling with keeping up with the snacks my children were eating. It seemed like they were always coming from the snack cupboard with a snack in hand and often the snacks were the same such as...pack after pack of gummy snacks. So this idea was a big help. Not only did it encourage better balance of snacks, but it took my memory out of the equation and put a stop to the 'but mom....'
Here's what I did based on the article I read. Take a 6x9 envelope and cut the top 2/3 off. That leaves you with a little holder. Then take index cards and write snack types on them: salty, sweet, fruit, vegetable, and protein are the ones we chose. I wrote examples on the back (and if you are raising budding lawyers like I am, it pays to do this). Then I put the cards in the 1/3 of the envelope and used some magnet holders I have (the magnet is on the back and it is like a clothespin so you can get it to hold item). I placed them on the fridge and boy, has it made this aspect of life simpler! There's no arguing about snacks, if the card has been used for the day, then that is it.
The first few days we ran into the problem of they would be so busy playing all day, they would save up all their snacks and want to eat them after supper, so I made one additional rule...only one snack after 7. Once the initial novelty wore off, they are now not even using all of the snack cards and are eating less to boot. A great situation!