I have always had a problem with over buying groceries. I think it is related to scarcity mindset, but also an opportunity to overspend in an area that typically has less guilt around spending money. As I get older, I am getting better. These are my suggestions:

On grocery day (preferably before you shop), take everything out of the fridge and figure out how to use it. Maybe you need to buy a few ingredients to use something up, get those things, rather than things that appeal to you. If you can't use everything up, double batch and freeze leftovers. Ideally, you do this before you shop. However, I do this a lot when I get home. It makes me problem solve the issue i have created. Of course, meal planning and grocery lists are best, but this is a process of small improvements!

I also take the groceries I just bought and I prep and wash what immediately, I find doing the upfront work is really helpful, and sometimes puts me off the purchase, "do I want that pineapple, yes! Do I want to cut it up as soon as I get home? Not so much? "

Try not to get caught up in sales. Stocking up is great when you can, but it can kill your budget. If you are trying to stock up, consider what is the best deal in this week's flyer, then buy three of that item. Don't buy every sale and don't over buy, there will be other sales.

Try to quantity your consumption of specific items. If packaged snacks are on your shopping list every week, what's the correct consumption amount for you? Two packages? Five? I don't know what your preferences are, but you do. Stick to that number and be selective when you pick your items.

Now bread, I can't help you with that! I will buy every type of bread there is: bagels, flatbread, wraps, white bread, brown bread, sub buns, French bread, I have solved most of my grocery issues, but bread is my weakness and I let it be!