Saw444 - congratulations on doing all this before you really need to. Really. So many people don't.
And, yes, a budget is a budget. Okay, so this time you can just draw the money you need, but you're right to say that it adds up, as you proved. Plus, it's the little things like coffees which burn money people don't realise they're spending.
Either, include ALL work food and drink in the food budget (and you should be able to) if it's a reasonable work purchase i.e. Canteen sandwich, 40p in the kitty for a cuppa OR say to your DH that it must come from his pocket money if it's 'designer' coffee - i.e. Breaktime £2.50 Costa everyday.
BUT, you will have to be strict with yourself as well - no sneaking stuff into the food budget that's really for you, even though you justify it well.
One of the best tips about budgeting I ever got was from my Great Aunty, who hated Debit Cards and used to keep all her money in a drawer in labelled envelopes. Then she'd take what she needed for the right things at the right time, and if she borrowed from one, it got paid back from another immediately. They were even arranged in the drawer in order of priority, so that the really critical stuff was at the back and hardest to pilfer from.
Obsessive, I know, but it worked. I don't think she ever paid a bill late in her life!