That's kind of impossible...
EXERCISE!
Dieting reduces fat system-wide. In men, stomach fat is the most problematic. It goes on there first, and without exercise to tone the abdominal muscles, it looks like it comes off last.
exercise... :) running works the fastest
i have had an exercise ball for a long time now and i really like it. an exercise ball conforms to your back, allowing you to exercise and flatten your abs without straining your back.
Exercise and quit eating fatty foods
running is a very good way of working your stomach
If you really want to lose weight in 3 weeks without dieting, you need to go on vacation with some friends. You will be having such a great time that you'll forget to eat, and you'll exercise without even realizing it (splashing in a pool, walking on a beach, horseback riding, etc).
You can easily get a flat stomach in 2-3 months without a diet plan but you have to drink a lot of water. Create an abdominal exercise routine and stick to it, every day. Plank crunches, bicycle crunches, and cross crunches will help to get your abs in 6 pack shape.
no
No sugar. Eat all healthy and lots of finer.
What I did was to quit drinking pop/soda and I did a lot of exercise. I noticed when I quit doing those things I gained some of the weight back. So you have to continue to exercise, otherwise you won't get anywhere. For more in-depth information, see the related question, further down this page, listed under "Related Questions."
You need to use more calories than you take in. So, you could lose weight through exercise only if you were using more than you ate.