The first few days have been a little scary for me. My kids have eaten a lot of snacks. They have always eaten a lot of snacks (and a lot at meals), but they ate snacks more often than I expected.
They were only able to chose healthy options. All less than optimal options were way too high for them to reach, or were in limited supply. Both kids went for crackers and string cheese often. When they ran out of the supply that was within their reach, they were out of that option until mom decided to move them lower.
They still ate their meals and they whined less about snacks. I think they enjoyed the freedom and control over their own choices. Nobody ate a whole bag of marshmallows or anything completely out of control. They didn't always snack in a balanced way, but since I can control what is within reach, I can move things when I see too much or too little of a particular food group. So far, things are going well with our experiment. We are going to give it a good trial and then reassess.