How can a 25 year olf lose belly fat?

Suck in abdomen. I did a consultation on a young woman who was terribly distressed about her belly fat. Come to find out, she was a competitive skater. I asked her if she was bothered by the belly fat when she was skating her programs. She told me "i guess not." she went on to say that when she was skating she would suck in her stomach! I suggested that she pretend she was always skating. It worked! :).
Diet and Exercise. You can't target weight loss from a specific area; you need to burn more calories than you consume. Eat healthy, cut out junk food and exercise several times a week. If your stomach is what you're unhappy with, you can tone up the muscles-sit ups are a good way to start. Anything that uses your abdominal muscles will add tone. Visit with your doctor or a dietitian to come up with a good plan.