No need to waste money on mass-gainer products, since they often contain a lot of junk, like high
fructose corn syrups.
It's so much easier and cheaper to make your own, using whey protein as a base.
1 cup of liquid (about 230ml, you can use milk, almond milk, etc.)
1 scoop of whey protein (about 40 grams)
1/3 cup of rolled oats (or oat flour)
2 tbsp peanut butter
Put all ingredients in a blender. Blend. Consume.
Pro tip: for some extra healthy fats, add in a tbsp of MCT Oil.
Of course this is just a simple base recipe, you can add more ingredients to increase the calories, or use whole milk. In this recipe we used unsweetened almond milk.