I try not to swear on public forums (or in life) but WTF??
How does any child "steal" food? It's family food?
Buy a limited amount of junk food, take your dc to the store with you to plan what you all need for the week. Give them some control over their food choices within discussed guidelines.
This food police stuff is crazy.
"No." Is not a discussion. Explain why you know sugar is bad. Then tell them that you expect them to make good choices for their own health.
Good choices are responsibilities that all of us need to make. Children rebel when pushed but glow when given control. They WANT to be in charge so give them appropriate choices and LEAD, don't punish.
Both of my dc are 100% height and 50% weight. Have been since babes.
They love various fruit and veg. I let them have access to the pantry and what juice that they wanted.
Our schedule has always been breakfast, snack, lunch, snack, dinner. If they are hungry at any time, they eat. Of course they have had conversations with us about the connection of food and their bodies/health/acne.
But I also pushed them to exercise with bikes, scooters, swimming, games and tossed them outside at snack time. I made good food fun. I listened to them and NEVER forced them to try food or made them eat something they disliked.
All of those things were done to me and from experience, its not a good parenting choice.
Help your dc understand how much better they feel by eating healthy food, limit bad food coming into your home and be a good role model.
My dc yell at me for poor eating habits.
Seriously, please stop punishing dc for eating. Teach them to eat when they are hungry and if they are bored, give them better choices than food.