Is a 14 year old girl who is 47kg and 165cm (5'5) underweight?
What are some ways to put on weight, by that I don't mean eating excess McDonalds, thus resulting in obesity. But I mean are there certain foods that are healthy yet make you put on a considerable amount of weight?
Most people think that protein is great and you should get as much of it as you can, but your body can only take in so much protein. After that limit, the protein no longer becomes protein in your body, instead it becomes fat.