I have always been severely underweight especially for my age I currently weigh about 79lbs and doctors do not seem to know why. My blood is fine so I assume it is just genetics but I am tied of being underweight. Other people have a hard time losing weight and talk about it more often not much about underweight issues, but I have a really hard time gaining weight as silly as it sounds I do not like being so skinny. Does anyone have any tips to gain weight?