How much protein to eat?

[cdamaden]

I’ve enjoyed the discussions about reducing mTor. I’ve been intrigued how that would work in the context of maintaining or improving muscle tone. I’ve seen several recommendations such as .8g protein per kg body weight. This article in the NyT suggests a much higher value.

Lift Weights, Eat More Protein, Especially if You’re Over 40https://nyti.ms/2Bf9mSE

The paper recommends 1.6 g per Kg. I wonder if there is a marker that can help us, like BUN, to find what our body needs while not creating unneeded mTor activation. Of course if you desire to be in ketosis that gives you another cap to consider.

Chris



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[slacker]

I find this appropriate amount of protein issue a tricky one. It's a great question Chris. I don't have an answer. I think by the time standard lab tests are abnormal, it may be obvious, especially for low protein levels in malnutrition.

[Orangeblossom]

I have read somewhere around 1g per kg, is a useful figure, but unsure, overall. Which would fall between your values, and be easy to calculate! Maybe it would also depend how much you are working out and doing weights, for example, too?

[Stavia]

I have read somewhere around 1g per kg, is a useful figure, but unsure, overall. Which would fall between your values, and be easy to calculate! Maybe it would also depend how much you are working out and doing weights, for example, too?

And how much you follow the mTOR hypothesis. Higher protein upregulates mTOR. Too low protein may increase the risk for sarcopenia in older people. And what about individual genetic variations.
Argh!! Rabbit hole.
Pick a number. I go for 1gm/kg. ish.

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[JimBG]

This is a great question and I don't think anyone has a precise answer. I believe that there is a dichotomy between what is needed for maximum muscle growth and optimal health and lifespan. The McMaster University review/analysis was looking at how to determine the impact of protein on resistance training in order to maximize protein synthesis and muscle growth. Hence their recommendations of 1.6g/kg/day and 0.4g/kg following resistance training. These recommendations are I think targeted primarily toward bodybuilders and athletes. On the other hand longevity researchers warn against excess protein. So Dr. Valter Longo in his new book on The Longevity Diet recommends that if you are under the age of 65 daily protein intake should be between 0.31 to 0.36 grams per pound and those over 65 should slightly increase their protein intake, and if doing resistance training 30 grams one to two hours afterwards. Also the other day Dr. Eric Verdin CEO/President of the Buck Institute tweeted the NYT article and commented "Work from the aging field says that excess protein consumption is associated with increased IGF-1 and increased cancer. Protein supplement buyers beware!!" Lastly I recall a podcast of Dr. Peter Attia (can't recall which one) who is into athletics and longevity and his struggle with this question. His recommendation is to consume just the right amount of protein that your individual body requires based upon your normal metabolic requirements, activity, muscle building, etc. and no more. How do you do that? No easy answer. He mentioned that possibility of measuring the level of nitrogen in one's urine to determine if there is an excess. Not sure how that can be done in practical terms.

[MarcR]

Examine.com updated their 2013 article on this topic today. 19 of the 33 linked references were published in 2014-2018, so it's a major revision:

How Much Protein Do I Need?

The U.S. Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg. This is considered to be the minimal amount of protein a healthy adult must consume daily to prevent muscle wasting when total caloric intake is sufficient. According to recent studies, however, the RDA for protein may not be sufficient for healthy young men, older men, or older women. These studies point to 1.2 g/kg as the minimum intake before the body starts downregulating important non-essential processes, from immune function to muscle protein synthesis. Even a reanalysis of the data used to establish the RDA suggests the minimum intake should be at least 1.0 g/kg.

A randomized controlled trial that confined healthy, sedentary adults to a metabolic ward for eight weeks provides the final nail in the coffin for the RDA. The participants were randomized into three groups [...] Each diet was equally hypercaloric: each participant consumed 40% more calories than they needed to maintain their weight. Yet, as shown in the figure below, eating near the RDA for protein resulted in loss of lean mass, and while this loss is so small as to be nonsignificant, the higher protein intakes were associated with increases in lean mass.

I recommend the charts in the article summarizing the study - very powerful.

The article distills the research into recommendations based on current state, activity level, and objective. For example, this is the one for me:

If you’re of healthy weight, active, and wish to keep your weight, aim for 1.4–2.2 g/kg (0.64–1.00 g/lb). Try for the higher end of this range, as tolerated, especially if you’re an athlete.

From 2014-2016, I targeted 1.9 g/kg. The recommendation came from a spreadsheet I found on a Reddit keto group. In 2017 I cut my target to 0.7 g/kg after reading about the perils of MTOR activation. This year, concerned by some subtle diminishment of muscle mass, I have been targeting 1.0 g/kg and have been working out more consistently. I have noticed improvement in my musculature, and after reading this article and some of the key references, I have decided to increase protein further to 1.6 g/kg, which aligns with this article:

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

The analysis noted that protein optimization accounted for about 9% of strength gains; of course, the lion's share comes from resistance exercise training.

The study also noted that "Older individuals are anabolically resistant and require higher per-meal protein doses to achieve similar rates of MPS, the primary variable regulating changes in skeletal muscle mass, compared with younger participants." (MPS = muscle protein synthesis)

For older adults (>50) who want to lose weight, this study suggests that keeping protein above 25% of caloric intake preserves more muscle mass during weight loss:

Effects of dietary protein intake on body composition changes after weight loss in older adults: a systematic review and meta-analysis

Some of the referenced studies used high-tech methods to track short-term variations in amino acids to calculate more precisely the saturation points at which further protein does not improve MPS. For example:

Increased Protein Requirements in Female Athletes after Variable-Intensity Exercise

and

Indicator Amino Acid-Derived Estimate of Dietary Protein Requirement for Male Bodybuilders on a Nontraining Day Is Several-Fold Greater than the Current Recommended Dietary Allowance

Pretty cool!

[apod]

I’ve enjoyed the discussions about reducing mTor. I’ve been intrigued how that would work in the context of maintaining or improving muscle tone. I’ve seen several recommendations such as .8g protein per kg body weight. This article in the NyT suggests a much higher value.

Lift Weights, Eat More Protein, Especially if You’re Over 40https://nyti.ms/2Bf9mSE

The paper recommends 1.6 g per Kg. I wonder if there is a marker that can help us, like BUN, to find what our body needs while not creating unneeded mTor activation. Of course if you desire to be in ketosis that gives you another cap to consider.

I've heard that muscle mass is maintained via exercise or diet, such that with regular weight training, paradoxically, you might not need as much protein on training days as you would on a rest day for maintaining lean mass. The paper from MarcR seems to confirm this notion. Ketones also seem to have a BCAA sparing / lean mass sparing effect.

I like the idea of "mTor stacking" where you can suppress it via fasting, exercise, and coffee (and resveratrol / other polyphenols?), then allow it to spring back to a higher degree than it might otherwise reach with a high protein, leucine-rich meal, seemingly reaping benefits on both sides of the spectrum. In this context, I would imagine "chronically elevated mTor" would be avoided (compared with say a western diet with protein + carbs at most meals throughout the entire day), although I've never seen a way to measure fasting / basal mTor. Perhaps mTor activation is more of an issue when other genes associated with fitness / physically-demanding eustress-rich activities are inactive (ie. the western diet / lifestyle model), and less of an issue when it's being used to build a lean resilient physique.

With BCAAs, Whey Protein Isolate, and a semi-high protein diet (~100-120g/d, sometimes more), my last BUN measured 14 mg/dL, where "BUN levels less than 15 mg/dL are associated with maximally reduced risk of death from all causes. As BUN increases above 15 mg/dL, mortality risk increases." Although, I took the blood test while in the middle of my fasting window.

Blood Urea Nitrogen: A Simple Blood Test For Determining Optimal Protein Intake:
https://michaellustgarten.com/2014/07/2 ... e-and-bun/

[MarcR]

I like the idea of "mTor stacking" where you can suppress it via fasting, exercise, and coffee (and resveratrol / other polyphenols?), then allow it to spring back to a higher degree than it might otherwise reach with a high protein, leucine-rich meal, seemingly reaping benefits on both sides of the spectrum. In this context, I would imagine "chronically elevated mTor" would be avoided (compared with say a western diet with protein + carbs at most meals throughout the entire day), although I've never seen a way to measure fasting / basal mTor. Perhaps mTor activation is more of an issue when other genes associated with fitness / physically-demanding eustress-rich activities are inactive (ie. the western diet / lifestyle model), and less of an issue when it's being used to build a lean resilient physique.

That's an intriguing speculation, apod. I love the idea that the real issue with MTOR is chronic elevation - very similar to the insulin story. Have you seen this article from P. D. Mangan?

Protein cycling diet for life extension

He's focused on IGF-1 (responding to a Valter Longo paper) and methionine rather than MTOR, but his idea is remarkably similar to yours. His rationale is complex with 8 referenced papers and a variety of other links - might be worthy grist for your mill.

With BCAAs, Whey Protein Isolate, and a semi-high protein diet (~100-120g/d, sometimes more), my last BUN measured 14 mg/dL, where "BUN levels less than 15 mg/dL are associated with maximally reduced risk of death from all causes. As BUN increases above 15 mg/dL, mortality risk increases." Although, I took the blood test while in the middle of my fasting window.

Blood Urea Nitrogen: A Simple Blood Test For Determining Optimal Protein Intake:
https://michaellustgarten.com/2014/07/2 ... e-and-bun/

Now that is fascinating. If I understand Lustgarten's insight correctly, protein suboptimization risk is a U-shaped curve with 15 at the sweet spot - we should eat enough protein to reach a BUN of 14 or 15. At lower levels we're courting sarcopenia, and at higher levels we're damaging our guts. (I'm not sure that Lustgarten actually understands the implications since he seems happy with his BUN of 8.)

The idea reinforces my move back to higher protein as my most recent BUN - from 2016 when I was targeting 1.9 g/kg protein - was about right (13). (Incidentally, my lifetime high of 21 was in 2009, about six months after I started my health improvement journey - I can only imagine what it was from 2003-2009 when I put my head in the sand and did no testing at all.) Guess I'll update my labs in a month or so.

[Jafa]

Thank you so much for this post MarcR. A timely wake up call for me to up the protein intake substantially. I’m doing bloods this week so will attempt to get a Bun test. I know I have lost lean muscle mass as well as every ounce of fat (seemingly). I was quite surprised recently how much trouble I was having with pushing my visiting grandson up the neighbourhood inclines. I hadn’t had this problem with other buggy bound grandchildren less than two years ago. Of course I have lost my bottom with those very important muscles for pushing. I am feeling a bit ‘got at’ presently. A dear doctor friend has told me to increase my calories for 3 months and lessen my fasting time. This morning at my annual dental checkup I was greeted with enquiries regarding my health status and told ‘you gotta get some weight on, girl’. I have been told by one workmate .. “ All this walking is fine, just do it with a bag of chips”. So reluctantly I am going to increase the calories and protein and have already begun weight training twice a week. Ketones will have to wait for now.

[Searcher]

So reluctantly I am going to increase the calories and protein and have already begun weight training twice a week. Ketones will have to wait for now.

Jafa,

Wise move. Excessively low levels of insulin tend to hasten muscle wasting. Balance is everything. And optimal practices vary with age. Grandparents generally can't afford to starve.

There's a lot to be said for eating and exercising in a way that enables you to do what really matters to you (such as pushing grandkids up slopes). Quality of life is always a useful criterion.