How to reduce belly fat?

I have come across many advertisement from day to day newspaper or Television and even in the internet where many organisations or people from different sects claim to reduce belly fat effectively. Are their claims carries the reality. Will it be effective. It may be medical or exercise or what ever the idea they claim. Should I try with this to reduce my belly fat.

just do sit ups, and other ab excercises, as well as start running or walking or something and you will see that fat go away.

cardio

Only drastic lifestyle changes will make you look the way you want to look. Don't watch TV anymore. Stop gorging on cheetos and twinkies. No more McDonald's. Eat only healthy food. Exercise. You do these things, and you WILL get back in shape.