Hi, you are not gainign weight because what ever you are eating it is not absorbing from your intestine. We have small projection Finger like structures called Villi which helps to absorb the nutrients from the food. Due to bad eating habits, pollution, drugs,toxins and other things has lost the capacity to absorb the nutrients. If you want to gain weight or lose weight we need to regenerate those villie first to absorb the nutritients. If you are serious about gaining weight please contact me at ehsan1@consultant.com or call me on 919880595504