Free food or not, you absolutely should join at least one club when you're in college. Clubs are not just a ton of fun, but also will help you to make long-lasting friends and connections that can be more valuable than your degree.
That said, joining a club or two will also keep you well fed. Most clubs have weekly or at least monthly events that offer free food -- typically pizza, snacks, or sandwiches. Even if you're not a member, most clubs don't care if you grab a slice as long as you stick around for the whole meeting.