Be sure to eat at noon, otherwise it will be bad for your health. You are only in the sixth grade, and you are still growing. Drink plenty of water during the day and pay attention to vitamin supplements, but you can skip meals at night, just eat some vegetables and fruits and don't eat anything at night. It is best not to drink water for 2 hours before going to bed. The amount of exercise can be increased appropriately. Search aerobics online. Don't keep running, your calves will get thicker.