The Sweet Spot for Protein Intake

The sweet spot for protein intake encompasses two goals which are at least in theory somewhat opposed to each other.

Goal 1: I want to get maximal hypertrophy from my weightlifting sessions.

Goal 2: I want to oppose the aging process, reduce disease risk, and maximize lifespan.

Why are these goals opposed to each other, at least in theory? The reason harks back to the growth-longevity tradeoff. Generally, the more an organism grows, the shorter the lifespan will be, due to the nature of mTOR and other biochemical mechanisms.

On the other hand, maximizing muscle growth from weightlifting entails eating a substantial amount of protein.

Maybe we can balance the two. Maybe it’s possible to maximize hypertrophy and retard aging at the same time. We need to find the right amount of protein, enough to maximize hypertrophy without compromising lifespan. I’m not saying that it can be done, but that’s what I’ll look at here.

How Much Protein to Maximize Muscle Gains

Most bodybuilders will tell you that the more dietary protein you have, the better. But there are limits to how much protein the body can use. For example, a study called Evaluation of protein requirements for trained strength athletes found that for strength athletes, a diet with 1.4 grams protein per kilogram of bodyweight produced a balanced state, whereas 0.86 grams was not enough, and at 2.4 grams, some of the protein was being burned for fuel and not used for hypertrophy.

These results are broadly in line with other studies, notably the widely cited and agreed upon calculations in the review by Lemon. He increased the recommendation by two SD to cover just about everyone. So it appears that hypertrophy is maximized at about 1.8 g/kg bodyweight.

As Lemon says in his article, the debate continues, since many, many factors, such as other dietary components, training intensity, age, must be taken into account. But let’s go with 1.8 g/kg.

That’s still quite a bit of protein, more than double the RDA.

Protein, Calorie Restriction, and Lifespan

The most robust treatment for the prolongation of lifespan in virtually every animal it has been tried on is calorie restriction. Animals, such as rats, that are fed 30% or fewer calories than ad libitum fed animals can live up to 50% longer, and with better health, less disease. In essence, they stay younger longer, so this treatment doesn’t just prolong old age.

It appears that the main macronutrient responsible for the effects of calorie restriction is protein. “Many of the effects of dietary restriction (DR) on longevity and health span in model organisms have been linked to reduced protein and amino acid (AA) intake and the stimulation of specific nutrient signaling pathways.” If calories are restricted but protein is not, little to no benefit appears; if calories remain the same but protein is restricted, much or all of the same benefit appears.

This also seems to be the mechanism with methionine restriction: restriction of this one amino acid causes less protein to be synthesized.

The means by which protein restriction causes the longevity promoting effects of calorie restriction seems largely due to a decrease in levels of insulin and IGF-1, which promote growth of all kinds, including cancer. People who are deficient in IGF-1 have a very low incidence of diabetes and cancer.

The Crux of the Matter

If you ever read articles on bodybuilding sites, you see that bodybuilders seek to raise levels of IGF-1 in order to build muscle. Human growth hormone’s effects are mediated by an increase in IGF-1. One way they seek to raise IGF-1, other than hormones and steroids, is through increased dietary protein.

So here’s the problem: does raising IGF-1 through higher protein intake in order to maximize hypertrophy lead to a higher rate of aging and greater risk of cancer and other diseases of aging? I’d say that it does.

Can we build muscle and decrease aging? There may be a way.

Systemic IGF-1 May Not Be Necessary to Build Muscle

Muscle growth seems to be much more linked to myostatin than it does to IGF-1. Quote: “… growth factor responses local to the muscle may be more important than circulating factors in contributing to muscle hypertrophy with resistance training.”

We don’t need large systemic increases in IGF-1 to promote hypertrophy. Therefore, at least as far as IGF-1 goes, we don’t need as much protein.

There’s some evidence that trained weightlifters and bodybuilders need less protein than beginners. Trained athletes use protein more efficiently, and beginners are packing on muscle like gangbusters, so this makes some sense.

Lowering IGF-1

Dedicated members of the Calorie Restriction Society who were eating ~1.7 g/kg daily of protein had IGF-1 levels of 194 ng/ml after several years of calorie restriction. That’s a high protein intake and represented, for them, about 24% of total calories. After dropping their protein intake to less than 1 g/kg for three weeks, their IGF-1 levels dropped by about 25% to 152 ng/ml. The problem with interpreting these results is whether these IGF-1 levels, both before and after dropping protein intake, are good or bad. I don’t know and don’t think anyone knows what level of IGF-1 conduces to lower mortality and longer life.


We don’t know which levels of IGF-1 are healthy and which conduce to aging. Another aspect is that IGF-1 levels are a relatively esoteric lab test that most people do not regularly get; I’ve never had one, for instance.

Would we be compromising hypertrophy from weightlifting by decreasing protein intake, or is there a sweet spot where we can have the best of both worlds: increased lifespan and robust muscle building. Again, the answer isn’t clear. I am however beginning to suspect that the bodybuilder’s standard of 1.8 grams of protein per kilogram of bodyweight daily may not be optimal for increased lifespan. Weightlifting is great, but perhaps the protein not so much.

If any readers have anything to add I’d love to hear it.

Updated: Pete (of Straightforward Fat Loss) alerted me to an article by bodybuilder Menno Henselmans called The Myth of 1 g/lb: Optimal Protein Intake for Bodybuilders. A number of studies are cited, all by recognized experts in the field, and this one is typical: Influence of protein intake and training status on nitrogen balance and lean body mass. In it, the authors state that elite bodybuilders needed only 1.05 g/kg protein daily to remain in nitrogen balance. Not only is this way below the usual cited figures, but it lends credence to what I stated above, that trained bodybuilders need less protein than beginners. Also of great interest, this figure is only slightly higher than the amount of protein that lowered IGF-1 levels in the members of the Calorie Restriction Society, cited above. If this is so, then it also shows that elite bodybuilders do not need high levels of IGF-1 in order to be who they are. (Possibly beginners do; that’s unknown at this point.)

So maybe we’ve found a sweet spot: slightly over 1 g/kg protein daily. This ought to provide plenty of support for muscle hypertrophy, assuming you’re not a beginner, and also prevent ultra-high IGF-1 levels. It comes with the caveat that we don’t really know the optimal IGF-1 level, although probably lower is better, other things being equal.

Another aspect not discussed in the original post is that of protein pulsing: one could eat plenty of protein on workout days, and less on off days, for a total of less protein. Since IGF-1 varies over a longer term, this should make for lower levels. In all of the research I’ve read on protein requirements for athletes, especially bodybuilders, never have I seen anything that addressed whether bodybuilders need this amount of protein only during the 24 to 48 hours after a workout, or always.

PS: A good infographic on how to increase protein intake can be found here.

PS: For more on maximizing muscle, see my book, Muscle Up.

PPS: Check out my Supplements Buying Guide for Men.


Leave a Comment:

Braivo says March 17, 2015

Perhaps IF can provide that balance. Dave Asprey has written on his blog about the benefits of a weekly, one-day protein fast (<15g). I have been experimenting, based a great deal on your writing, with a 7-day cycle incorporating both growth and autophagy.

I lift weights W and F, and eat adequate protein and calories W-Sa to facilitate growth for 36 hours after the lifting session. Then Su-Tu I do 16-hour fasts by skipping breakfast, avoiding protein altogether on Tu.

Of course I can't test the longevity aspect, but I've made steady strength gains and reaped the mental clarity benefits of fasting.

@Joe_E_O says March 17, 2015

I have gone 180 degrees on this subject. I have been eating about 1 gram of protein per pound of body weight over the last 12-18 months. I have made great gains in terms of strength, but I have increased many of the signs/symptom of metabolic syndrome. I think by chronically ingesting protein (which is insulinogenic) I increase my insulin resistance. So I am off my body-builder diet and back to a more paleo diet – probably .8-1.6 gram/kg body weight. Other thing that I am doing:

1) Supplement with Vinegar. I have a dose of vinegar before each meal. Sometime via a salad, sometime just drinking vinegar
2) Supplement with Soluble Fiber. Just like the vinegar – I try to have a does before each meal. I will add psyllium husk to soup or eat muffins made with psyllium husk (much better than it sounds)
3) General Low Carb/Moderate protein diet.
4) Eliminate insulinogenic protein (Dairy and Whey Protein)
5) Avoid Saturated Fat or should I say I don’t supplement with saturated fats like Jimmy Moore and the BulletoProof executive.
6) Intermittent Fasting.


Joe E O

    Jim says March 18, 2015

    Wow, this is great info. I basically do the same thing but not the vinegar, this is my daily diet:

    FAST till 2
    Juice Fruits+Veg.
    Juice Fruits+Veg
    Meal: 2xCARBSProteinFAt

    adjust ratio, quantity depending on if im cutting/maintaining

Baron says March 17, 2015

So, what does one eat if one wants to go low-carb and reduce protein? Basically, eat a lot of nuts and olive oil?

    @Joe_E_O says March 17, 2015

    Nuts, Olive Oil, Avocado, Egg, Chicken, Turkey – that all works.

    There are some great videos online by Dr Jason Fung. He is a nephrologist who treats (cures) lots of T2DM – with the protocol I am using (fasting, paleo diet, supplemting with vinegar and fiber)

    Joe E O

      Undercover Slob says January 11, 2016

      Sure, but don’t the last 3 contribute mightily to protein intake? They can be eaten in moderation for sure, but they also are more protein concentrated than say, sausage. Maybe that’s the ticket, sausage.

      Undercover Slob says January 11, 2016

      Sure, but don’t the last 3 contribute mightily to protein intake? They can be eaten in moderation for sure, but they also are more protein concentrated than say, sausage. Maybe that’s the ticket, sausage.

Jason says March 18, 2015

Just curious how this looks like with macros – are we talking 80% of our calories comes from fat, so 2400 calories would mean 213g of fat with the rest being divided between protein and carbohydrates?

It sounds like any bulking based approach, like high carb/protein, should be short lived relative to the time we’re not trying to stimulate insulin.

    Joe E O says March 18, 2015

    I think we are talking about 60 of calories from fat. I personally have never been able to get to 80% unless I “supplemented” with fat. Here is what I had for Breaky: hot and sour soup (sour kraut, corned beef, broth, soy sauce, vinegar, ginger, miracle noodles) and a flax meal wrap (flaxmeal, eggs, psyllium hush, seasoning) – and this what my MyPlate said the macros were:

    Cals 500.1
    Fat 31.2
    Chol 669.4
    Sodium 2749.7
    Carbs 16.3
    Fiber 20.2
    Prot 33
    Sugars 5.1

    So I shoot for about 1800-2100 calories with about 120 grams of protein. I am eating in a compressed window today as I start my fast at noonish

Mark Sanders says March 18, 2015

Note that Jack Lalanne, the big exercise/body building expert from the 50s and 60s lived to age 97.

    P. D. Mangan says March 18, 2015

    Yes, of course he wasn’t huge by today’s standards. He also had a brother, Norman, who did no exercise and lived to be older.

Strength and longevity are compatible - Rogue Health and Fitness says December 20, 2015

[…] bodybuilders need only about 1.1 grams of protein per kilogram of body weight to maintain muscle mass. Adding muscle may require somewhat […]

ProudDaddy says January 11, 2016

You’ve probably commented on the following study by Longo’s group, but just in case

It clearly shows that high protein significantly (both clinically and statistically) reduces total mortality in us olduns!

Daniel Antinora says February 11, 2016

I feel like I might be a bit unique and that my protein need might be higher than average.

Is there an efficient and somewhat inexpensive way to test your nitrogen balance?

    P. D. Mangan says February 11, 2016

    Unfortunately, there is no easy way to test nitrogen balance, because it not only involves testing all inputs (food and drink) but all outputs – urine and feces. Not something done every day.

    However, I’m not aware of any stark differences in protein requirements, so if an experienced bodybuilder requires 1.2 g/kg, seems unlikely that you would require 2.

Why Being Vegan Is a Bad Idea - Rogue Health and Fitness says May 22, 2016

[…] US RDA for protein is 0.8 g per kg bodyweight. That’s too low. Some bodybuilders (bros) recommend 2.2 g or more per kg, and that’s too […]

Ben says September 29, 2017

Perhaps hypertophy isn’t that important. Just strength and power

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