What Popular Protein Research Got Wrong

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Sometimes I come across popular ideas in nutrition that can’t possibly be true despite being so enforced by many industry figures I look up to. That being said, I know nobody is infallible, not even credible coaches and researchers, so while it’s risky to disagree with the majority, I think we can all agree that discovering the truth is most important.

Where am I going with all this?

Well, many science-based coaches have been overly promoting this idea that more protein is better for body composition. More specifically, the claims that I want to tackle today are the following:

These ideas stem from a few published studies done by deeply credible researchers, so if you don’t look into the deeper details of science as a whole, it’s easy to regurgitate the same questionable conclusions everyone else is saying.

No Beef Bro

The lead researchers of the popular studies I’m questioning are Jose Antonio and Bill Campbell, both of which I usually agree with.

Mainly, I disagree with the common interpretation of these topics regarding a few of their studies. I mean no disrespect to them personally, despite how passionately I might press into some points. Let’s start with the first claim.

Is Protein Really Less Fattening?

Antonio et al conducted a set of studies looking at very high protein intakes, the kind of intake that would make your local butcher rich.

The first study compared a low protein group of 1.8 g/kg/day to a high protein group of 4.4 g/kg/day in trained lifters (1). 4.4g/kg/day is 2x your bodyweight in pounds per day, so a 200 pound person in this study would have to eat 400 grams of protein daily. Both groups were instructed to eat their baseline diet while the high protein group was instructed to eat more protein to reach their target.

After 8 weeks, both groups kept the same body composition with no statistical difference despite the high protein group reportedly being in an 800 calorie surplus along with eating more carbs and fat.

The second study similar in design, compared a low protein group of 2.3 g/kg/day to a high protein group of 3.4g/kg/day in trained lifters (2). The high protein group had a 300 calorie bigger surplus along with also eating more carbs and fat.

After 8 weeks, both groups statistically recomped. The low protein group gained more weight while the high protein group kept the same weight. The high protein group also lost more fat, so they essentially had better recomp results.

The third study, compared a low protein group of 2.6 g/kg/day to a high protein group of 3.3g/kg/day in trained lifters (3). The high protein group ate about 400 more calories daily. After 4 months, both groups had no significant body composition changes with no differences between groups.

At first glance, these studies make it look like protein is impossible to be fattening even in a caloric surplus. Many coaches will interpret it this way and end up posting contradicting content. They’ll make one post about any nutrient in a surplus causing fat gain, while the very next day, they’ll make a post about how overeating protein can’t make you fat. C’mon bro.

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So What’s the Truth?

Mechanistically, we know a surplus of protein can cause fat gain (4,19). While it’s true that the excess protein itself rarely turns into actual fat, the excess will be oxidized for energy leaving less carbs/fat to be burned off resulting in more of those nutrients getting stored as fat (5).

In essence, physiology doesn’t give you any free passes. Any excess of energy will result in stored fat after muscle building limits are maxed out.

This means for protein to be as magical as the Antonio studies suggest, it must have energy expending effects powerful enough to burn off all the additional calories you ate from extra protein along with the additional carbs/fat consumed in all 3 high protein groups.

Are The Suggested Explanations Logical?

The proposed explanation by the authors was a combination of an increase in exercise expenditure, NEAT, and the thermic effect of food (TEF).

Exercise expenditure couldn’t have made a difference because both groups did the same training program with the same volume. In fact, in the first study, there was a noticeable trend for the lower protein group doing and gaining more volume load. It’s also important to note that in these studies, the workouts were unsupervised which is another limitation to consider.

Furthermore, in all 3 studies, no group significantly gained more muscle or performance, so there is nowhere to point to for protein causing additional exercise related expenditure.

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That brings me to the next point. NEAT.

NEAT stands for non-exercise activity thermogenesis. It’s just a fancy word meaning the calories you burn from non-formal exercise like blinking, brushing your teeth, or double tapping a picture on the gram. I don’t know of a single study showing protein as a sole variable increasing NEAT, let alone to any meaningful degree.

Moreover, we do certainly know NEAT more likely decreases with weight/fat loss. In the second study, the high protein group lost more weight than the low protein group, so this is a stretch to claim NEAT skyrocketed to a jawdropping rate.

Lastly is TEF which is how many calories you burn from digesting food and it’s the weakest way our body burns calories leaving more skepticism. Protein does have the highest TEF when compared to carbs and fat (6,7).

However, this is only in isolation and is at most 20-25%. When eaten within mixed meals, even with triple the protein content, the thermic effect is not different or enhanced (8,9).

There is also no additional TEF benefits to overfeeding long term with excess protein (10). Even if there was, for the Antonio studies to be plausible, TEF would have to exceed 100% to negate all the additional protein calories along with the extra carbs/fat consumed by the high protein groups. If this were the case, extremely high protein diets would be the new miracle diet that cancels out all calories more magical than any spell taught at Hogwarts.

Long story short, even in combination, the 3 most feasible explanations falls considerably short. And without these explanations, you have to impossibly defy the laws of thermodynamics in order to get the mind blowing results seen in the Antonio studies.

Uncovering the Truth

The culprit that explains these radical results are simple. Self-report. Despite the subjects being trained lifters, humans are notorious for making errors and self-reporting data is often concluded to be deeply unreliable (11).

Oftentimes, university studies involve subjects as mutual friends which naturally comes with social, personal, and physical expectations/incentives. In other words, you don’t want to be known as that guy that drops out of the study. You’d rather stick it out for numerous reasons even if it means not fully adhering to the difficult requirements whether intentionally, subconsciously, or mistakenly.

The studies had pretty high dropout rates as is. One can only assume how difficult it must be for the remaining participants in the high protein groups to reach 3.3-4.4 g/kg/day of protein without compensating their normal diets for 2-4 months straight. If done with the prescribed protocol, it should feel like withstanding the discomfort of eating a giant meat buffet except you have to tolerate it again and again for months without breaks. Good luck with that.

Replication Doesn’t Match

A different lab replicated a similar study in trained lifters, but didn’t get congruent results with Antonio (12). Although they also involved self-reporting, they had a more doable protein target for the high protein group. This study overfed 2 groups with diets equal in calories. One group had a protein intake of 1.1g/kg/day compared to a high protein group of 2.5g/kg/day.

Both groups gained the same amount of fat. Even with the low protein group eating a very suboptimal dosage, the high protein group doubling their protein intake didn’t protect from further fat gain in a separate lab.

 A 2013 Meta-analysis of 15 randomized controlled trials also supports that additional protein does not particularly protect you from fat gain (13).

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Furthermore, Bray et al conducted 2 similar studies in non-lifters using a metabolic chamber (14,15). For those who don’t know, metabolic chambers are rooms that detect and control all the energy in and out. Food is directly fed to subjects, energy is accurately measured, and there’s no need to ponder about the human race making mistakes or misreporting data.

These uber expensive, yet high quality studies compared 5% to 15% to 25% of caloric intake as protein while all groups were overfed a 40% surplus.

In both studies, fat gain was the same between all 3 groups even in the high protein eating about 3 g/kg/day.

Muscle gain was significantly lower in the low protein group, but was the same between the middle and high protein group indicating what some coaches already know to be true. Once sufficient protein intake is met, there’s no additional body composition benefits to more. Eating more doesn’t spare fat gain, increase fat loss nor does it add on more muscle mass.

This brings me to the next study I’m addressing.

The Controversial Campbell Study

In Campbell’s study, if you just read the abstract (synopsis for research papers), you would think more protein is better for recomping (16).

This study compared a high protein intake of at least 2.5g/kg/day against a low protein group with at most 0.9g/kg/day in trained aspiring female physique athletes.

This study designed and controlled the training program very well (kudos for that), but didn’t control for caloric intake, so we have no clue what the energy balance difference was between groups. They also didn’t control for non-muscular water gain which can confound results (18).

The results found the high protein group recomped significantly better by gaining more muscle and losing more fat.

The 0.9 limit in the low protein group is so questionable from a design perspective because that’s such a suboptimal dose for lifters which the authors even addressed in the paper describing it as what average sedentary people consume.

So the interpretation shouldn’t be “more protein increases your odds of recomping or enhances the effects of it.” The interpretation is what I mentioned earlier, there are no body composition benefits to protein beyond an already optimal dose (1.6-1.8g/kg/day) which the authors touched on (17).

In fact, besides the Antonio studies, all the other studies they cited in his paper supports this. As you go from suboptimal protein towards optimal, you get better body composition results, but going past optimal has not been shown to be better.

If that were the case, all you can eat shrimp at Red Lobster would produce some of the leanest most jacked customers ever.

Another confounding factor in this study was protein timing. The high protein group got fed an optimal pre and post-workout protein timing protocol while the low protein group got a suboptimal version which they mentioned as well.

Furthermore, I don’t disagree with the authors that body recomposition can happen in a deficit or surplus along with occurring in trained lifters, I just disagree with the interpretation of more protein enhancing body recomposition.

Once optimal protein intake is achieved, body composition benefits are maximized. Any further benefit or increased odds of recomping would depend on other factors like training, body fat levels, genetics, training experience, etc.

So What Are the Takeaways?

Ultimately, I don’t fault Jose Antonio or Bill Campbell. They’re great researchers who did what they can with their budget and reported the data as follows. That being said, all of us, researchers or not have a responsibility to dissect truth and teach accurate conclusions which I don’t think many coaches are doing when referencing these studies.

Physiologically, it just doesn’t make sense for protein to have these exaggerated effects past an already optimal intake which many fitness enthusiasts are already consuming.

So here are some crucial truths you need to grasp that will challenge some of the common regurgitated advice you hear:

  • Protein in a surplus can still make you fat.
  • Additional protein past an optimal dose isn’t less fattening than carbs or fat.
  • Additional protein past an optimal dose doesn’t increase your chances of recomping.
  • Additional protein past an optimal dose doesn’t enhance the effects of a recomp or other body composition related effects.

Don’t get me wrong, protein is important for making you look good naked, but once you get enough, eating more doesn’t prevent consequences or speed up results. Period.

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  1. Antonio J;Peacock CA;Ellerbroek A;Fromhoff B;Silver T; “The Effects of Consuming a High Protein Diet (4.4 G/Kg/D) on Body Composition in Resistance-Trained Individuals.” Journal of the International Society of Sports Nutrition, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/24834017-the-effects-of-consuming-a-high-protein-diet-44-gkgd-on-body-composition-in-resistance-trained-individuals/.
  2. Antonio, Jose, et al. “A High Protein Diet (3.4 g/Kg/d) Combined with a Heavy Resistance Training Program Improves Body Composition in Healthy Trained Men and Women–a Follow-up Investigation.” Journal of the International Society of Sports Nutrition, BioMed Central, 20 Oct. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4617900/.
  3. Campbell, B., et al. “The Effects of a High Protein Diet on Indices of Health and Body Composition – a Crossover Trial in Resistance-Trained Men.” Journal of the International Society of Sports Nutrition, BioMed Central, 1 Jan. 1970, jissn.biomedcentral.com/articles/10.1186/s12970-016-0114-2.
  4. Charidemou, Evelina, et al. “A Randomized 3-Way Crossover Study Indicates That High-Protein Feeding Induces De Novo Lipogenesis in Healthy Humans.” JCI Insight, American Society for Clinical Investigation, 20 June 2019, insight.jci.org/articles/view/124819.
  5. Stokes, et al. “Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training.” MDPI, Multidisciplinary Digital Publishing Institute, 7 Feb. 2018, www.mdpi.com/2072-6643/10/2/180/htm.
  6. Swaminathan R;King RF;Holmfield J;Siwek RA;Baker M;Wales JK; “Thermic Effect of Feeding Carbohydrate, Fat, Protein and Mixed Meal in Lean and Obese Subjects.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/4025189-thermic-effect-of-feeding-carbohydrate-fat-protein-and-mixed-meal-in-lean-and-obese-subjects/?dopt=Abstract.
  7. R;, Binns A;Gray M;Di Brezzo. “Thermic Effect of Food, Exercise, and Total Energy Expenditure in Active Females.” Journal of Science and Medicine in Sport, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/24589371-thermic-effect-of-food-exercise-and-total-energy-expenditure-in-active-females/?dopt=Abstract.
  8. Ravn, Anne-Marie, et al. “Thermic Effect of a Meal and Appetite in Adults: an Individual Participant Data Meta-Analysis of Meal-Test Trials.” Food & Nutrition Research, Co-Action Publishing, 23 Dec. 2013, www.ncbi.nlm.nih.gov/pmc/articles/PMC3873760/.
  9. WW;, Li J;Armstrong CL;Campbell. “Effects of Dietary Protein Source and Quantity During Weight Loss on Appetite, Energy Expenditure, and Cardio-Metabolic Responses.” Nutrients, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/26821042-effects-of-dietary-protein-source-and-quantity-during-weight-loss-on-appetite-energy-expenditure-and-cardio-metabolic-responses/.
  10. Sutton, Elizabeth F., et al. “No Evidence for Metabolic Adaptation in Thermic Effect of Food by Dietary Protein.” Wiley Online Library, John Wiley & Sons, Ltd, 29 June 2016, onlinelibrary.wiley.com/doi/full/10.1002/oby.21541.
  11. CJ;, Archer E;Pavela G;Lavie. “The Inadmissibility of What We Eat in America and NHANES Dietary Data in Nutrition and Obesity Research and the Scientific Formulation of National Dietary Guidelines.” Mayo Clinic Proceedings, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/26071068-the-inadmissibility-of-what-we-eat-in-america-and-nhanes-dietary-data-in-nutrition-and-obesity-research-and-the-scientific-formulation-of-national-dietary-guidelines/.
  12. Spillane, Mike, and Darryn S Willoughby. “Daily Overfeeding from Protein and/or Carbohydrate Supplementation for Eight Weeks in Conjunction with Resistance Training Does Not Improve Body Composition and Muscle Strength or Increase Markers Indicative of Muscle Protein Synthesis and Myogenesis in Resistance-Trained Males.” Journal of Sports Science & Medicine, Uludag University, 23 Feb. 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC4763837/.
  13. G;, Schwingshackl L;Hoffmann. “Long-Term Effects of Low-Fat Diets Either Low or High in Protein on Cardiovascular and Metabolic Risk Factors: A Systematic Review and Meta-Analysis.” Nutrition Journal, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/23587198-long-term-effects-of-low-fat-diets-either-low-or-high-in-protein-on-cardiovascular-and-metabolic-risk-factors-a-systematic-review-and-meta-analysis/.
  14. Bray, George A, et al. “Effect of Dietary Protein Content on Weight Gain, Energy Expenditure, and Body Composition during Overeating: a Randomized Controlled Trial.” JAMA, U.S. National Library of Medicine, 4 Jan. 2012, www.ncbi.nlm.nih.gov/pmc/articles/PMC3777747/.
  15. Bray GA;Redman LM;de Jonge L;Covington J;Rood J;Brock C;Mancuso S;Martin CK;Smith SR; “Effect of Protein Overfeeding on Energy Expenditure Measured in a Metabolic Chamber.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/25733634-effect-of-protein-overfeeding-on-energy-expenditure-measured-in-a-metabolic-chamber/.
  16. Campbell BI;Aguilar D;Conlin L;Vargas A;Schoenfeld BJ;Corson A;Gai C;Best S;Galvan E;Couvillion K; “Effects of High Versus Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training Program.” International Journal of Sport Nutrition and Exercise Metabolism, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/29405780-effects-of-high-versus-low-protein-intake-on-body-composition-and-maximal-strength-in-aspiring-female-physique-athletes-engaging-in-an-8-week-resistance-training-program/.
  17. Morton RW;Murphy KT;McKellar SR;Schoenfeld BJ;Henselmans M;Helms E;Aragon AA;Devries MC;Banfield L;Krieger JW;Phillips SM; “A Systematic Review, Meta-Analysis and Meta-Regression of the Effect of Protein Supplementation on Resistance Training-Induced Gains in Muscle Mass and Strength in Healthy Adults.” British Journal of Sports Medicine, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/28698222-a-systematic-review-meta-analysis-and-meta-regression-of-the-effect-of-protein-supplementation-on-resistance-training-induced-gains-in-muscle-mass-and-strength-in-healthy-adults/
  18. Haun, Cody T, et al. “Effects of Graded Whey Supplementation During Extreme-Volume Resistance Training.” Frontiers in Nutrition, Frontiers Media S.A., 11 Sept. 2018, www.ncbi.nlm.nih.gov/pmc/articles/PMC6141782/.

  19. Charidemou . “A Randomized 3-Way Crossover Study Indicates That High-Protein Feeding Induces De Novo Lipogenesis in Healthy Humans.” JCI Insight, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/31145699/.

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