Since it is the third grade, learning is very tense and busy, and nutrition is extremely important. You must keep up to get good grades! I don't agree with your diet to lose weight, but you must control your diet when you lose weight. According to your situation, I'll give you some advice.

1. Have breakfast. A bag of milk, a boiled egg and oatmeal are also good.

Usually, if you are hungry, you'd better eat apples, cucumbers and bananas. It is worth mentioning that bananas are not only delicious, but also high in potassium and calories.

Eat less staple food and more vegetables. If possible, don't eat any staple food for dinner, just eat vegetables and eat meat properly, such as fish. It is recommended to eat less chicken. KFC and McDonald's should go less in the future, especially Hamburg.

4. Before 9 am, you can eat freely. After 9 pm, it is best not to eat, drink or eat before going to bed.

5. Don't overeat.

Sports.

1. I like playing tennis very much I don't know if it will help me lose weight, but I have time to play. It should help, but I need good physical fitness and develop endurance. I recommend it to you out of personal preference.

2. Swimming is good, and a good choice for weight loss exercise can increase the previous endurance. Especially in summer, looking at other people's good figure will also motivate you to lose weight!

3. running? Never experienced it. I only occasionally go to the gym to run with my classmates. Very tired, not recommended.

4. taekwondo. When I was practicing Taekwondo, my clothes were twisted by water, which cost me a lot of money, second only to tennis, but also improved my flexibility and endurance and strengthened my physique.

Your speed is very slow. I think it's because of your poor health. Exercise more, your physical fitness will go up, and your sports performance will naturally go up.

Increase? I don't know much about it, so I can't give you advice, but I was really not too tall or even short when I was in primary school and junior high school. After entering high school, I suddenly grew a lot taller, and now I am normal height. Actually, don't worry too much about height. Some people just grow a little late, but they grow better than well-developed people!

I wish you success in losing weight and gaining weight during your holiday!