Past tense- WIBU?!

[PipLongStockings]

I am a single parent-teacher DS age 10 is slightly overweight but eats well, just eats loads.
We are tight for money this month as had large car repair bill and he has accompanied me to Iceland for a extra tight budget shop on an old love 2 shop voucher, trying to stretch for enough to cover the week.
We went yesterday- 24 hrs later (all by himself) he has finished a 1L blackcurrant squash, ate his 150g treat and finished off his brothers, finished a further bottle of drink, spilt blackcurrant on the side and not cleared it up then put a whole loaf of bread in it and said I'm not eating that now. A 400g punnet of grapes, tub of diced pineapple and several ice pops. He ate his and his brothers bananas, oranges and youghurts.
After speaking to him yesterday, he repeated it all again today and I lost it.
Where is your respect for our family, don't you understand sharing, what are we going to have the rest of the week, why do you think everything is for you etc etc. He looked very upset and kept apologising but I said you apologised yesterday and repeated it again today.
WIBU? I can't hide food/lock away, he needs to have some self control. He does this surreptitiously- not sneaking food away just hiding in the kitchen.
So not to drip feed, this is not a.new thing but is exasperated by the strict school holidays budgeting.

single parent not single parent-teacher!

OP.

It sounds like a compulsion. 10 year olds SHOULD be better at impulse control but some are not.

Is he bored? Lonely?

Sounds like a recipe for diabetes. Stop the squash and the treats. Only get plain food in for a bit, he'll learn.

And YWNBU to tell him off.

That's a huge amount of food. You need to sit down and ask whether he is eating because he's bored, why he doesn't think about it etc

That is a massive amount of food. Could it be an eating disorder?

Sounds like he has a bit of an issue with food, especially if he's hiding it and sneaking it. Is this worse in the school holidays? He may be eating from boredom and need help structuring his time. I'd suggest though that he has an accessible treat box for the day and all of the other food is put away out of reach (locked?) it's all very well saying that he needs to learn self control but your family can't afford to wait for him to do so.

I can't hide food/lock away, he needs to have some self control.

Yes you can. It doesn't matter that he 'should' have self control. What matters is that he doesn't, so you need to physically stop him.

I still lock my kitchen and mine is a teenager now. She has always needed to see the boundary.