Protein is considered the king of satiety and fat loss in the health and nutrition world. However, it is very important to note that many protein heavy foods(eg. steak, eggs, chicken) haven't undergone the same structural degradation as other sources of carbohydrates(from potatoes to simple sugars) and fats(from nuts and vegetables to pure oils) have underwent. We do have protein shakes that still maintain some structural components such as thickeners, frothers and emulsifiers in many cases... but what happens when you completely degrade protein down? Lets TRULY compare pure protein with pure carbs... does it fare better when it comes to reducing energy intake or inducing satiety?
In this first study(1), protein (Clear Protein 8855, a 90% source of whey protein, colorless, further refined, non-cloudy and odorless) is tested compared to water to note any changes in satiety and hunger. Utilizing 1%, 2% and 4% protein in water reduced energy intake by a very small amount(8%) in the following meal. This was not sufficient to impact food intake 2 hours later. The study was repeated again(2) in the future but this time protein(Clear Protein 8855) up to 4% (348 kJ or 83 calories) was compared with up to 10% sucrose water and a sweetened water control. Beverages were matched for volume, color, flavor and sweetness. A challenge meal was provided 2 hours later after these preloads. Neither protein nor sugar enriched waters had any impact on ad lib energy or macronutrient intake with no energy compensation for the caloric beverages.
If we are to truly compare sugars to proteins, lets degrade proteins further into a metabolized isolate as well, akin to sugars and pure oils. Luckily, such a study(3) was conducted using a pure metabolized form of protein(CMP or Caseinomacropeptide) up to 2%. CMP was tested against water at various timings and it was found that it had no impact on hunger, satiety and total energy intake on the current meals and food intake throughout the day.
When it comes to satiety, it seems like protein fares no better than sucrose when ingested in its purest and beverage forms which may answer the question whether replacing sugars in sodas with proteins would do us any good. Another important point to note is that "watery" beverages are mainly used to quench thirst and not stomp hunger which may explain why certain liquids(eg. soups) may be more satiating(a different can of worms to be honest!) than quenching beverages. This current article ties in nicely with our previous one where we discussed how beverages and certain liquids can contribute to global obesity. There are many tasty zero calorie alternatives to caloric beverages such as diet sodas, sparkling water and certain kambuchas which can be consumed. As far as protein is concerned, studies like these don't seem to be too promising when it comes to leveraging protein to reduce hunger and induce satiety. Well, they do say... take down the big suit, mansion and car and you get a normal man underneath. As a food company that reverse engineers foods from isolated macronutrients, the extreme focus on pushing specific macronutrients without considering the mechanisms of food form is not a solution to ending the world's obesity crises and leads to more confusion and totally missing out on the mechanisms that make food satiating, filling and potentially helpful in reducing energy intake.
Lastly, if someone's pandering "high protein" or "high fat" or "high carb", the first question you should be asking them is, "What the hell are you talking about because for one person peanuts may be "high protein", for another they may be "high fat" while for that other guy, they may be "high carb?? In other words, what is your source and form of macronutrients?" Even the infamous satiety index(4) first indicates satiety of specific foods as more or less satiating and THEN derives conclusions about macronutrients from that.
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