I'm a 20 year old male 5ft 10 inches tall and i weigh 140 . i feel like i'm too light, are there any ways to help gain good healthy weight back ?

140 lbs: 1: What is the size of the male members of your family? If close to yours you are doing OK. 2: If not you should see both a dietitian and an athletic trainer. 3: Go online to "NuVal" where you will find a list of 100 items - some good, some not so good, and some not good at all. See how your current diet stands in relation to these items.