How should a 13 year old lose weight?

Stop eating too much and start exercising on a daily basis. Specifically, eat 4-5 fist sized portions a day. Avoid TV and video games and instead go for a walk/jog.

These are good ideas but - if you are 13- this might be a completely fine weight for you! You may be growing quickly and your hormones are causing you to gain weight quickly. This does not mean that you need to lose weight. I went from 95-123 pounds in one year as a teen but I was never over weight. Now I am in my thirties and still weigh about 124- which is a good weight for me. ( I am average build and 5ft 4 ) Don't obsess- it's a complete trap! Believe me...