How do you lose twenty pounds at a young age?

To lose 25 lbs. at this age, you should ask your physician. If you're not comfortable asking, then you can jog at least 2 miles each morning for at least 5 weeks. You can also work out at the gym.

There's no reason to. You shouldn't feel the need to lose it young just because others do so, or pressure you to do so.

Yes because once your fit at a young age you would have no problem lossing weight once your body is growing and besides you would have a great health

The only way to do that is to have liposuction done. Any other way is unhealthy. A healthy weight would be between 5-10 (At most) pounds a month. There is just no way to lose that much that fast. It...

Get better eating habits and exercise more. Skip everything sugary and fatty. No sodas, nothing deep fried. Expect to need 4-6 months for that weight loss - if you manage to control your diet.