I am a girl turning 17 in May I weigh 42 kg and I am 1,56 m tall.I did a test that said I am underweight and so do all my friends, I am quite active and have a lot of muscles because I do gymnastics.I used to weigh 47 kg(last year beginning of December and stated losing the weight to the end of December) so I dropped a few kg. I don't know what to do because I want to look healthy,I tried eating more but I just don't gain weight,I want to do it in a healthy way and I want to gain 8 kg... Does any one have some things I can try out...

What type of "test" did you go to a doctor or clinic for a BMI and other real tests?

I did a BMI test

You need to add protein to your diet! If you want to add muscle you want to add protein (1 gram per pound body weight wanted per day) and you want to spread it out over 6 meals a day!

This really isn't tricky! Protein, work out (gymnastics, weight training and cardio), proper diet and you should gain quickly!

Mark