Water vs. Protein Shake: Which Is Better for Fat Loss?

Water vs. Protein Shake: Which Is Better for Fat Loss?

Protein shakes are considered a staple by many people in the fitness industry and are sometimes a solid component of a weight loss diet. However, do they really help? Do they provide satiety or reduce energy intake?


This study(1) consists of two single blind randomized crossover trials that determines whether protein sources in beverage form provide satiety and lower energy intake compared to water. In the first trial with 32 male volunteers, a preload of 20g of casein, whey, pea protein, egg albumin or maltodextrin was consumed in a beverage form 30 minutes prior to an ad lib meal. Only pea protein and casein were able to marginally lower energy intake during the meal while the other forms of protein drinks had a weak compensatory response and as a whole ended up adding some extra energy to the meal. Compensatory response is as follows(100% means full compensation of calories from the drink):

  • Casein: 110%
  • Pea Protein: 103%
  • Whey Protein: 62%
  • Albumin: 56%
  • Maltodextrin: 51%

In the second trial, 20g of casein, whey, pea protein and water were consumed as a starter to the meal and there was no difference of the drinks on ad lib food intake. Total energy intake was also higher in all preloads compared to water.


Protein is very important and an essential macronutrient which shouldn't be skipped. However, for fat loss and reducing hunger, protein shakes are barely any better than water when it comes to helping induce satiety which may help with lowering energy intake long term. Even that may have very little to do with protein content and more with its rheology, texture or structure which may be dependent to some extent on the interaction between proteins, emulsifiers and binding/thickening agents. It may be more ideal to add protein to the diet using a viscous(eg. cheese) or structured(eg. steak) form or use protein powder as an ingredient in a satiating food recipe(we use protein isolates in our Energy Pods) to help induce satiety. With that being said, some protein shakes taste good and can still be consumed occasionally to supplement a diet that is thoroughly lacking in protein.




Fahad is the founder of Ketogeek and hosts the Ketogeek Podcast, a world class health show about food, nutrition and health. He is into resistance training, Ashtanga yoga, calisthenics and various forms of training styles. Armed with a idealistic goals distilled in a world of realism, his goal is to help the world make a better place. He leads a life of extreme generalism or as he describes it, 'The Renaissance Lifestyle'.


It never ceases to amaze me how prosaic, pedestrian, unimaginative people can persistently pontificate about classical grammatical structure as though it's fucking rocket science. These must be the same people who hate Picasso, because he couldn't keep the paint inside the lines and the colors never matched the numbers.”
― Abbe Diaz