Here’s how they compare in terms of protein.....
>>> 30g Protein powder (made up with 200ml water) = 97kcal, 25g Protein & 1.6g Carbs
>>> 200ml semi-skimmed milk = 98kcal, 6.8g Protein & 10g Carbs
What’s the verdict.....
An average whey protein shake delivers approx 25g protein compared to milks 6.8g, so in order to obtain the same amount of protein from milk; you would need to consume approx 700ml of the stuff, almost 3.5x the quantity of fluid!
Ever tried consuming that amount of fluid within the 30 minute anabolic window after training!? Blooaaattteddd comes to mind!!
In terms of Protein delivery & efficiency...The WINNER is ---> Whey Protein shake!