10-15% goes towards groceries. I tend to save as much as I can on groceries by looking for great deals, using coupons and rewards points as well as buying house brand items for certain goods like liquid soap and cooking oil. As for dining out, not counting work lunches, I'd spend about $50-$100 per meal (depending on how fancy the place is).
20-25% because we are a big family (extended family to be exact). What I do is to prepare a weekly menu already and strictly follow it so we stay within the budget.