I think it might be better to work backward in this case. First determine your discretionary income, and then allocate that to the various areas you'd spend money on. It's nice to hear "you should spend X% of your income on food" but maybe for you, it's more important to eat out 3 time a week including one super-fancy per month than it is to go on vacations.
Food is obviously a requirement, unlike travel or electronics, but fancy or expensive food is not. So I'd say that the food allocation of your discretionary income should be the amount that's above a certain baseline - a reasonable, "thrifty" amount.
This might be something like assuming 5 inexpensive take-out meals per month (say $8 each) and cooked food the rest of the time (maybe $5-6 per day). So a rough estimate of your baseline might be $200 or so.
Now how much do you like to eat out, or buy lobster and duck to cook at home? How much do you travel? If you've got $5000 to do what you want with, would you rather take a $3000 trip and have an extra $2000 to spend on food? That's an overly simplified case, but you get the idea...