For people who are into body-building, a protein shake is almost a mandatory supplement. Since protein is needed in the building of muscles, a protein shake is seen as a sure way of meeting the body's daily protein requirement to maximize muscle building.

Protein shakes are a complicated affair of timing and right mixture according to an article by Ed Vanstone for Men'sHealth. There is a recommended pre-workout protein shake that needs to have the right amount of carbs to the speed of the absorption of nutrients to the muscle tissues. And there is even a post-workout shake and a bedtime casein-rich mixture to help muscles grow as one sleeps.

Yet, not everyone is convinced that drinking protein shake is the best way to take this macronutrient. Johnny Adamic,in his article for TheDailyBeast, insists that protein is for eating and not drinking. To back his point, Adamic cites Megan Wolf a registered dietitian based in New York City and owner of the website MeganWolf Nutrition. Wolf suggests that people should eat their calories or, at least, try to limit calories obtained from drinks because the brain interprets calories from food differently than calories from drinks.

 According to Wolf, most people are capable of drinking more calories than they could eat. She attributes this to the fact that it could take longer for the brain to register that the stomach is already full. Since drinking can be done faster than eating, it is possible to over drink more calories than over eat. Of course, Wolf points out the eating faster would also achieve the same effect.

Wolf is not actually dismissive of the whole meal replacement idea. She concedes that meal replacements could become a part of a healthy diet. But then again, if given the choice between eating and drinking, she would recommend people to eat instead of drinking their calorie requirements. And she has a point. A protein smoothie just can't beat the satisfactions one gets from chewing a juicy piece of steak.