Hai, Intially don t go for any protein supplements. as your BMI is normal. nutrilite or endura mass whatever supplement is not appreciated when you have natural food source. get an opinion from your dietician with your daily food intake compared with gym output. First eat protein nourished foods like Almond,cashew,channa,soyabean,peanut in your daily food intake. as you are practicing Gyms you can take sprouted nuts,grains before you start. Add jaggery,black gram,and dal prepared with ghee. take diary product like milk,yogurt,chesse,butter etc. Add banana and tuber vegetables. if you take non veg take meat ,fish consistently. take good amount of water. avoid fried,junk food,caffeinated drinks. This will nourish you in healthy way and gain weight. thank you hope i answered you.