I am very thin ,iwant to increas my body weight and some fat also.i also tryingto used banana shake many medic?

u should eat non-veg every day or if u r veg then eat oily stuffs or lots of healthy food in large quantity and don't involve urself too much in physical task and don't go for some medic solution because they will only harm u. Finally eat n eat n no work(or less work) will definately make u fat.