Reduce your intake of white bread, pasta and rice. These foods have little to no nutritional value. When eating these types of foods, choose whole grains.
Fill up on fiber. Fiber is essential to obtaining a six-pack stomach -- because it reduces bloat around the abdominal muscles and keeps you feeling fuller longer. High fiber items are beans, fruits and vegetables. Teens need 30 to 35 mg per day, this is very attainable if you eat natural foods.
Snack on nuts, yogurt and lean meats. These foots have lots of protein, which helps build and repair muscles. Since you'll be working your muscles, this is essential.
Cut out soda and sugary sports drinks. Even diet soda can cause abdominal bloat and cravings for sweets. Sugary sports drinks are wasted calories.
Reduce the amount of sweets you eat. Drastically cutting out sweets, especially if you enjoy them, is not a good idea. This deprivation can lead to eating an excessive amount, setting you behind on your progress. Enjoying a piece of dark chocolate every day will not wreck your diet.
Schedule cardio workouts. Getting your heart rate up will help burn that extra fat around the abdominal muscle. Great forms of cardio workouts are running, bike riding and rowing. The American College of Sports Medicine recommends doing 30 minutes of moderately intense cardio exercises five times a week.
Enroll in a Bikram yoga class. Yoga is very effective at building up your muscles -- it is also great at helping you relax. Bikram yoga is done in a room that's 105 degrees. This temperature helps you sweat out impurities and toxins, this can help burn off the extra layer of fat around and reduce water weight.
Work your upper abdominal muscles. Regular sit-ups offer a limited range of motion, for best results do your sit-ups on a stability ball. Once you become comfortable with this, hold a hand weight on your chest while doing the sit-up for extra resistance.
Focus on the lower muscles. Women, even teenage girls, tend to store most of their fat around lower abdominal muscles. Work away this bulge by doing reverse abdominal crunches. Lie on your back, arms at your side, and thighs at a 90 degree angle to the floor. Using your lower abdominal muscles only, bring your knees to your chest.