We can't buy our health for any amount of money, so it's very important to take care of your health. First of all, you may follow a diet which will help you to keep slim and feel better. There are many kinds of them. But at present many young people think that to be on a diet means to eat nothing, that is absolutely wrong. Following a diet you should eat healthier food.
But the best way to keep fit is to do sports. Small changes in your routine like climbing the stairs instead of using the lift or cycling instead of taking the bus to school, can help you to keep strong. In conclusion I must note that it's not enough to follow only 1 point from the list, but if you haven't done anything like that so far, you'll have to start doing at least something.