I'm 19 years old and I weigh 140... Im 5'10?

I understand your plight I used to be very skinny I weighed 135 pounds at 5 feet 9 inches I now weigh 157 pounds all of this weight gain was from a proper diet, not supplements. Gaining weight is about working out, yes, but the most important factor is DIET. I would suggest you use this link, a href="http://www.eatright.org/programs/rdfinder/" rel="nofollow"http://www.eatright.org/programs/rdfinde…/a to find a registered dietitian preferably a CSSD that stands for, certified specialist in sports dietetics's. A dietitian, CSSD or not, will work with you to crate a healthy diet and or exercise plan to gain weight quickly and safely. The best of luck to you.