Is calorie restriction unsafe ? is 1500 too little for a 17 year old girl ?

Balanced diet: Avoid fad or overly restricted diets. You may lose weight, but are more likely to gain it back quickly. A healthy diet with balanced nutrition is the best choice. Use low fat milk (skim or 1% is best), low fat meats and cheeses, lots of fresh vegetables, fruits, and whole grains. Get at least 1 hour per day at least 3-4 days per week of active exercise.