For those that have tried to use a good weight gaining protein powder diligently for a period of time and it is not getting the kilos on you can look at adding other products to your weight gaining protein powder to increase the calories per serve. A good easy way of doing this is by adding 1-2 tablespoons of flaxseed oil to your shakes. Flaxseed is a very healthy unsaturated fat that is very high in calories for a small serve. By adding this the calories in your shake skyrocket, thus putting you in a positive calorie state and helping you get over the line for gaining weight.