I am underweight. I don't have an eating disorder; I just have a fast metabolism. I want to know how I can gain some weight and not stick out like a sore thumb for being so thin. - Giana*
An unfortunate side effect of the increase in people who are overweight and obese is that naturally thin people now might feel even skinnier. If you have always been thin for your age or height, then it's probably perfectly normal for you and you're not actually underweight. In this case there is no need to gain weight. If you recently lost a good amount of weight, though, or you have other concerns about your weight, talk to your doctor.