Are any of you underweight?

I would suggest going to a store like GNC where they have a large variety of products. They sell shakes for weight gain and things like that. The people who work at those places usually know what would work best. You should also excercise. Lift weights, that kind of thing to build muscle which will put on a few lbs and give you more definition

my BMI is just on the edge for goin in underweight. i need to gain weight also. find my thread, there are tips already.

If you work out, there are all sorts of things you could do. If you can go to a gym, you can ask them to help devise a personal plan to help you gain weight. Things like weightlifting(doesn't have to be like bodybuilding, just maybe dumbels and that sort of thing) or boxing or something like that can help build muscles which would help you gain weight. But I like someone elses suggestion to get pregnant! That helped me put on loads of weight! Problem with that is that a lot of thin people will just go straight back to being thin anyway.

It's ok to work out, even if you're skinny. If anything, it will help you gain muscle definition. If you want to gain weight, eat three big meals a day instead of several smaller ones, to help your metabolism slow down. You could also drink protein shakes. Have you talked to your doctor? There could be something he could suggest.

You could get pregnant.

yep but lower than you.

yea...50 kg