Losing weight is a combination of eating healthy foods, getting enough exercise and getting a decent amount of sleep. There isn’t a safe way to lose 50 pounds quickly. You can, however, lose 6–10 pounds in a month, and that alone should make you feel better.
Ask your mom or dad to help you with a healthier diet.
Do you play a sport? Is there one that you can start? Pick a sport that requires a lot of running around like basketball or soccer.
Also, you’re still growing, so it’s normal for your weight to not match your height. When I was in middle school, I was a chubby kid (not saying you’re chubby, by the way). In HS, I joined the wrestling team and dropped about 20–25 lbs and stayed fit throughout HS. After HS, I quit playing sports and got fat again. Then I moved to a city where I had to walk all the time and ate healthier food and got skinny again. Then I moved to the South and ate a bunch of good southern food and stopped walking got fat again. And so on.
Lastly, you may want to find out if you have a problem with your metabolism, which is the engine in your body that turns your food into energy. Next time you go to the doctor, tell him/her that you want to lose weight and that you would like to make sure nothing is wrong with your metabolism. (Usually, this is about whether your thyroid gland or another gland is working properly.) There are blood tests that can tell you whether everything is normal.
Don’t take diet pills. They’re bad for you. Period.