Losing weight is very hard to do, but did you know that individuals who were born thin have a hard time gaining weight? There are numerous reasons for being underweight; some of them are from eating disorders, chronic diseases, and stress.  Most elderly people become underweight; this is the result of gradual loss of taste and smell, thus having loss of appetite. Thankfully, there are weight gain supplement available. There many kinds of supplements to choose from and choosing the right one can be troublesome. Before choosing which supplement to buy, you need to research online for reviews from other people who have already tried the product, that way you can have better understanding which one is best for you.