The more time you spend with your clients, the more questions you’ll be asked about nutrition.

And for good reason. The two or three hours a week you spend with them in the gym are no match for the 21 meals and countless snacks they consume on their own time. Until their training and nutrition are in sync, they won’t get the results they’re paying you to deliver.

The questions change with the whims of the celebrity-industrial complex, but there’s one constant: protein.

Over at the curl rack, every dude-bro and fem-bro has some opinion about bro-tein for bro-gainz.

Their doctors, meanwhile, give them the opposite message. They’re telling everyone with a BMI north of 25 to eat less and move more, while pooh-poohing the importance of protein and sending everyone out the door with a photocopied list of all the foods they should avoid.

With all due to respect to my friends in white coats and tight T-shirts, both sides are full of hot air and nitrogenous compounds.

Here’s what science has to say about the role of protein for health, body composition, and performance. I included footnoted references for those who, like me, enjoy diving into the deep end of the data pool.

1. How much protein do you need?

We’ll begin with a basic fact that I don’t think anyone disputes: To maximize muscle gains following resistance training, your clients need dietary protein (1).

The question, then, is how much it takes to get the job done.

Let’s start with clients who’re cutting calories with the goal of getting leaner and lighter.

Human studies show that 0.7 grams of protein per pound of body weight per day is best for retaining lean body mass—muscle, bone, and everything else that isn’t fat (2-5).

Which is awesomely precise, but mathematically complex for the average person. Here’s a much simpler frame, one that will get most of your clients close enough:

• Women: 4 x 30

• Men: 4 x 40

That is, four meals a day with 30 grams of protein per meal for women or 40 grams for men.

READ ALSO: Five Ways to Help Your Clients Lose Weight. 

2. How do they come up with that target?

Researchers account for two main items:

First is the leucine threshold. This is the 2.5 to 3.5 grams of the amino acid leucine that you need to jump-start the muscle repair process (7-9).

Next are essential amino acids, which provide the raw building blocks for muscle protein synthesis. As little as 6 grams of EAAs could be enough (10, 11).

3. Is there any benefit to going over these amounts?

Not much, as shown in a study that came out earlier this year (6). It was a meta-analysis—a combination of data from previous studies—with this conclusion:

"With protein supplementation, protein intakes at amounts greater than 1.6 grams per kilogram per day do not further contribute resistance training-induced gains in fat-free mass."

For a 100-kilogram/220-pound guy, that’s 160 grams of protein per day.

It’s much higher than your doctor would recommend (the RDA clocks in around 60 grams per day), but lower than the 1-gram-per-pound-per-day target that bro scientists use as their gold standard.

There may be other benefits to eating more, since protein is highly satiating and may help you eat less overall. But you’re probably better off filling up on all the other healthy, nutrient-rich foods that make up a balanced diet.

4. How much should you have at once?

The more protein you have in any given meal, no matter the source, the easier it is to get the leucine and EAAs you need for muscle protein synthesis and to hit your daily target.

To maximize the acute anabolic response, you need about 0.4 grams of protein per kilogram per meal, across a minimum of four meals per day (12). So a lifter who weighs 100 kilograms/220 pounds would shoot for 40 grams per meal. A female athlete who weighs half that much could get the job done with 20 grams.

Contrary to popular belief, you can use more than 30 grams of protein at once. In one study, for example, 40 grams consumed before bedtime was shown to be effective (13).

5. Which protein sources are best?

Encourage your clients to focus on whole foods most of the time. Animal sources like fish, chicken, beef, pork, and eggs offer the highest-quality protein for building muscle. That is, they’re complete proteins, containing all the essential amino acids, with enough leucine to cross the threshold.

A serving size of 5 ounces of meat or fish will typically get you in the neighborhood of 30 grams of protein. Eight ounces will get you to 40 grams. For convenience, you can get 40 grams from two scoops of most protein supplements.

You’d need seven eggs or five cups of milk to reach 40 grams. So while they’re both awesome sources of high-quality protein, they aren’t the most practical stand-alone options.

6. Do you need BCAAs?

Short answer: no. If you’re getting enough protein from whole foods and supplements, you don’t need to pile on additional branched-chain amino acids (14, 15). Two scoops of whey protein isolate, for example, contains 10 grams of BCAAs, half of which is leucine.

As one study noted:

“t is reasonable to conclude that there is no credible evidence that ingestion of a dietary supplement of BCAAs alone results in a physiologically significant stimulation of muscle protein.” (16).

You could make a case that they’d be useful for a client who’s on an extremely low-protein diet, or who just isn’t hungry enough to reach the amounts shown in the research I’ve cited. In that case, BCAAs could help your client get across the leucine threshold of 2.5 to 3.5 grams at each meal (17). 

7. Should you account for the protein in foods like nuts, seeds, and vegetables?

Life is too short to count the protein grams in broccoli. Not only is there very little total protein in the foods I mentioned, what they have is typically low in leucine and the other BCAAs.

It’s much simpler to track the amounts in the high-protein foods I listed in point number five.

8. Does protein timing matter?

There was a time when the most dedicated muscleheads thought they had to slam down a protein shake containing exactly 34.7 grams of protein within 27.7 minutes of putting down the last weight on their last set.

I’m exaggerating, but not by much.

Yes, there is an anabolic window, but it’s not nearly as narrow as we used to think. Once you account for total protein across the entire day, the specific timing of each dose isn’t especially important (18-20).

It’s a pretty simple message for your clients: Get some protein one or two hours before training, and then an hour or two afterward. Your body can take it from there.

9. What about vegan protein?

Many plant-based proteins are low in either leucine or EAAs. So your vegan clients have two options:

1. Use complete protein sources

These include:

• Soy*
• Buckwheat
• Hemp
• Chia
• Quorn mycoprotein (Fusarium venenatum, aka soil-dwelling saprotrophic nonpathogenic fungus) **
• Most sprouted grain***
• Rice****
• Pea

* Contrary to bro-science lore, eating soy won’t ungender your male clients. But, speaking as a guy, I personally wouldn’t make it my primary source of protein.

** As appetizing as it sounds (and who doesn’t love their nonpathogenic fungi?), there have been reports of adverse reactions among those sensitive to molds (22).

*** These are whole-grain seeds that have started to grow; they typically have less starch and better nutrient availability, and are easier to digest.

**** It’s only effective in higher amounts, or when you mix it with pea protein. It’s the supplemental version of the classic rice-and-beans combination.

2. Use more protein

In a study in which subjects were given 48 grams of either rice or whey protein after training, there was no difference in muscle growth over eight weeks (21).

Summing Up

I hope this serves as a handy guide for your clients who’re confused over the conflicting claims they see online. But if it’s still too long or complicated, you can simplify this list to two basic options:

1. Super-simple option:

* For female clients: 4 x 30 (four meals with at least 30 grams of protein per meal)

* For male clients: 4 x 40 (four meals with at least 40 grams of protein per meal)

Reaching 30 grams is easy: 

• ½ chicken breast
• 2 chicken thighs
• 1 cup of cottage cheese
• 1 cup of soybeans
• 1 cup of rice + 1 cup of black beans
• 5 to 6 ounces of meat or fish (a serving that’s about the size and thickness of your client’s hand and fingers, or two checkbooks)
• 5 eggs
• 4 glasses of milk
• 1 ½ scoops of a typical protein supplement

2. Nerd-herder math option:

Multiply the client’s body weight by 0.7 to get the total amount of protein per day. Divide by the number of meals and/or snacks your client typically eats.

So if the client weighs 200 pounds, the math tells us he should shoot for 140 grams of protein per day—35 grams per meal spread over four meals.

This should cover most of the questions your clients will have about protein. For everything else … yeah. Good luck with that.

Nerd Fuel (References)

1. Phillips SM. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr Metab (Lond). 2016;13:64.

2. Walberg JL, Leidy MK, Sturgill DJ, Hinkle DE, Ritchey SJ, Sebolt DR. Macronutrient content of a hypoenergy diet affects nitrogen retention and muscle function in weight lifters. Int J Sports Med. 1988;9(4):261-6.

3. Mero AA, Huovinen H, Matintupa O, Hulmi JJ, Puurtinen R, Hohtari H, et al. Moderate energy restriction with high protein diet results in healthier outcome in women. J Int Soc Sports Nutr. 2010;7(1):4.

4. Mettler S, Mitchell N, Tipton KD. Increased protein intake reduces lean body mass loss during weight loss in athletes. Med Sci Sports Exerc. 2010;42(2):326-37.

5. Layman DK, Evans E, Baum JI, Seyler J, Erickson DJ, Boileau RA. Dietary protein and exercise have additive effects on body composition during weight loss in adult women. The Journal of nutrition. 2005;135(8):1903-10.

6. Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, et al. 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. Br J Sports Med. 2018;52(6):376-84.

7. Norton LE, Wilson GJ, Layman DK, Moulton CJ, Garlick PJ. Leucine content of dietary proteins is a determinant of postprandial skeletal muscle protein synthesis in adult rats. Nutr Metab (Lond). 2012;9(1):67.

8. Breen L, Churchward-Venne TA. Leucine: a nutrient 'trigger' for muscle anabolism, but what more? J Physiol. 2012;590(9):2065-6.

9. Norton LE, Layman DK. Leucine regulates translation initiation of protein synthesis in skeletal muscle after exercise. The Journal of nutrition. 2006;136(2):533s-7s.

10. Rasmussen BB, Tipton KD, Miller SL, Wolf SE, Wolfe RR. An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J Appl Physiol (1985). 2000;88(2):386-92.

11. Kato H, Suzuki H, Mimura M, Inoue Y, Sugita M, Suzuki K, et al. Leucine-enriched essential amino acids attenuate muscle soreness and improve muscle protein synthesis after eccentric contractions in rats. Amino Acids. 2015;47(6):1193-201.

12. Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. J Int Soc Sports Nutr. 2018;15:10.

13. Trommelen J, van Loon LJ. Pre-Sleep Protein Ingestion to Improve the Skeletal Muscle Adaptive Response to Exercise Training. Nutrients. 2016;8(12).

14. Dieter BP, Schoenfeld BJ, Aragon AA. The data do not seem to support a benefit to BCAA supplementation during periods of caloric restriction. J Int Soc Sports Nutr. 2016;13:21.

15. Jackman SR, Witard OC, Philp A, Wallis GA, Baar K, Tipton KD. Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans. Front Physiol. 2017;8:390.

16. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017;14:30.

17. Churchward-Venne TA, Burd NA, Mitchell CJ, West DW, Philp A, Marcotte GR, et al. Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men. J Physiol. 2012;590(11):2751-65.

18. Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10(1):53.

19. Aragon AA, Schoenfeld BJ. Nutrient timing revisited: is there a post-exercise anabolic window? J Int Soc Sports Nutr. 2013;10(1):5.

20. Kerksick CM, Arent S, Schoenfeld BJ, Stout JR, Campbell B, Wilborn CD, et al. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr. 2017;14:33.

21. Joy JM, Lowery RP, Wilson JM, Purpura M, De Souza EO, Wilson SM, et al. The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance. Nutrition journal. 2013;12:86.

22. Hoff M, Trueb RM, Ballmer-Weber BK, Vieths S, Wuethrich B. Immediate-type hypersensitivity reaction to ingestion of mycoprotein (Quorn) in a patient allergic to molds caused by acidic ribosomal protein P2. The Journal of allergy and clinical immunology. 2003;111(5):1106-10.