Hi Alice,
Whether you met on a dating site or in real life, you don’t owe anything to a guy who pays for your meal on a date.
He chose to go out with you and pay for the date. This doesn’t guarantee that you will like him or that the date will work out.
As long as you know that you are going on these dates sincerely and not just to take advantage of guys by getting them to pay for your meals, you have nothing to feel guilty about.