Eat Healthy at regular time, join some sports club that make u run. Running help u to lose weight very easily. But dont eat too much after u ran. Eat portions that make u half full. That's it for every meal. Lastly sleep well.
Exercise eat healthy food. But do not I repeat do not just start a diet gradually start backing off of junk food. Remember YOUR BODY MAY BE STORING MATERIAL SO IT CAN GROW. Or it may think it is starving.
First throw out all food that isn't beneficial. Throw out any beverages that aren't beneficial. Drinks can add a lot of calories to your diet. And most drinks do nothing for you. The only thing you should be drinking is water,milk,and juice. Limit juice to one to two 8 oz glasses per day. And it needs to be 100% juice, not a juice drink,or juice beverage. Don't be fooled by the 100% sign, check the nutrition label. Don't eat foods with more than 100 calories per serving unless its really good for you. Don't eat foods that "don't have a significant level of Vitamin A,C, or Calcium. Also if you get a food with higher than 10% carbs it should contain fiber in order for your body to break it down properly instead of storing it as fat.
ExTrEmE diets and exercises are not the way to go if you want to be fit. The best way to become fit and slim is to just eat healthier and to regularly do small, simple, yet helpful exercises. A small jog around your neighborhood can help your leg muscles, a few push ups or just lifting up something a bit heavy can work your arm muscles, and planking on a slightly narrow surface with your legs and upper-torsso can help you develop strong abs. As for eating habits, cutting down on your intake on sugars(mostly artificial), carbs, and caffeine can really help. Try eating more fruits and vegetables and less grains. If you want a long lasting and healthy looking form, there is something called a "Paleo Diet", It really does help keep a life long healthy figure. Here are some good websites on paleo diets: http://thepaleodiet.com http://www.nerdfitness.com/blog/2010/10/04/the-beginners-guide-to-the-paleo-diet/ http://www.doctoroz.com/episode/paleo-diet-craze-does-it-work
Hope this helps! also you are still young don't worry so much about your weight as much as just being a healthy person! :-)