It is less pure, containing around 5 % lactose as well as a few grams of carbs and a couple to a few grams of fat per serving. (kingofthegym.com)
While there are fewer grams of fat in the steak, fat is much more calorie dense and comes to 9 calories per gram whereas protein sits at 4 calories per gram. (chriscoulsonfitness.com)
This gives you the amount of calories you have for carbs, because one gram of protein contains approximately 4 calories and one gram of fat contains approximately 9. (legionathletics.com)