I have twin boys. One son was dx type 1 diabetic in 2008. It was new and I had more fears and questions than answers. So no snacks in the house till I could get a grasp of the new diet changes and expectations. Both my boys did sneak snacks, normal I guess. Usually, I tried not to keep fun snacks in the house to prevent us all from over-indulging. I was trying to lose weight anyway. But they seemed deprived and lacked self control when outside of the home. The very thing I was trying to avoid was happening, overeating and a unhealthy sense about food.
Being a single mom, couldn't afford much, so got creative. I had to change for their sake. When they were about 12 years old I tried a snack budget. Every 2 weeks we would go to grocery store, and they each had a $5 budget to buy snacks. It could not be cookies, cakes, or candy and it had to keep them for the 2 weeks.
It was and is a great learning experience for all of us. They each had they own snacks, they learn to budget, and they have to police themselves to have the snacks stretch out the 2 weeks. If they ate all snacks in 1 week, there was no replacement till end of the 2 weeks. I did it with them, same budget and all. So I knew it could be done.
Within their budget they found cereal snack bars, pudding cups, yogurt, crackers, etc. I like apple sauce and lance cheese crackers and peanut butter. And it actually last 2 weeks. One time my son blow it on more expensive items like 8 pack of Gatorade and a few packages of trail mix. He quickly learned that he use his entire budget but had very little for snack. While Gatorade was nice after a hot day of practice, it did not satisfy him as snack nor did it last 2 weeks. So for the remainder of the 2 weeks he had water and pbj sandwich. Boring! The next time, he stayed in budget and kept focused on fun snacks than anything else.
My son with type 1 diabetes didn't sneak any more snacks, because he had his own. It was no longer a race or competition to eat the best or most snacks than the other. Occasionally, they’d swap a snack. They didn't feel deprived and when out with friends they didn’t lose control eating every sweet, chocolaty, salty, fatty snack they saw.
They are now 14 years old and still look forward to their snack shopping. I sometimes hear them planning their next trip. Of course, I did have to increase the budget a little, based on increased prices and increase appetite for active teenage boys. Now I will show them the wonders of coupons.
It worked for us. I hope it helps you.