I am 20 years old and am getting married in July. My stomach isn't that big, but I do want to lose some fat in that area before I get married. I've heard many things about both sit-ups and crunches and was wondering which one is better to do. I currently do about 40 sit-ups three times a week, as well as using the Roman Chair at the gym, which I can only do a few of. I try to eat healthy, avoiding sweets and fats. Is there anything else I need to do? Thanks!