Protein and longevity

Nutrition Q&A [Moderated]
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I know you’ve discussed protein intake ad nauseam already, but this is a slightly different topic.

Your recommendation for protein intake is 1.6 g/kg. This is nothing out of the ordinary, maybe a little lower than the usual 1.8-2.0 g/kg you hear pretty much everywhere in the fitness community. This figure, however, is still double the amount that the WHO recommends, which is 0.8 g/kg. But what’s interesting is that in the ageing research community, the recommendation is even lower. Here’s a quote from an article from Time magazine:

“Exercise researchers say more protein is often better—even in amounts well above the 56 grams a day (and 46 grams, for women) recommended by the Institute of Medicine … But talk to a disease and longevity researcher, and you’ll get a very different answer—one that sure won’t please Paleo dieters.”

First I think it’s worth posting this explanation by Dr Jason Fung (of Obesity Code fame) about the origin of the 0.8 g/kg figure:

“So the international group recommended that normal healthy people should get roughly 0.6g/kg/day. In order to make sure everybody was covered, the WHO added 25% (2 standard deviations) above the mean to get 0.75 g/kg/day which sometimes gets rounded up to 0.8 g/kg/day. In other words, 97.5% of the healthy general population loses less than this 0.75 g/kg/day of amino acids. This is not a low standard. This is a very, very high standard of protein intake.”

The obvious question is what’s the problem with excess protein? Dr Valter Longo (another well-known ageing researcher) has done some work on the effects of protein on ageing. I won’t post tons of claims here but I will give a quote from the article summarising the general findings:

“Longo’s research shows cancer rates increase nearly 400% among Americans who get 20% or more of their daily calories from protein, compared to those who restrict their protein intake to 10% of their daily calories. Risk of mortality also jumps 75% among the heavy protein eaters … there are several important confounding factors … but Longo says even if you cut out fatty, additive-stuffed cuts of meat—fast food burgers, breakfast sandwiches etc.—there’s still plenty of evidence to suggest protein consumption fuels disease and early death.”

I thought these were some wild claims but it appears that this is the consensus among ageing researchers, and that they’ve replicated these findings, which is why most of them recommend a much lower protein intake – about 0.4-0.5 g/kg. Of course this would be higher if you’re training or have a special condition, but that’s the number they advise in general.

I know you guys don’t like experimental research but maybe you can share some insight into this, particularly in relation to resistance training and whether low-protein (< 1 g/kg) is plausible for maintenance.

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Our protein recommendations are 1.6-3.1g/kg/day.

There are many different dietary patterns that comport with health promotion, but in general, high protein diets studied in many epidemiological papers are heavy on refined foods and low in fiber. When the fiber is corrected for, high protein diets do the same as vegan diets for health outcomes, which was shown by the Oxford study.

To be clear, no, there’s not plenty of evidence to suggest protein fuels disease, though excess calories, ultraprocessed foods (particularly in a calorie surplus), low fiber intake, high saturated fat intake, and the accompanying SES all play a role.

As an aside, Dr. Fung is not someone I hold in high regard, as his practices are not inline with the evidence. In simple terms, he is a quack.

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To be honest he seems very clickbaity to me, with article titles like “these people ate LESS, and gained MORE weight” (some insignificant difference under very specific experiment conditions), and likes to reduce everything to insulin (“it doesn’t matter how strong your willpower is, how much exercise, etc… when I’ve got this …” and pulls out an insulin syringe). But we can ignore him, the quote only concerned a historical fact.

On protein restriction, you are right that saturated fats/processed foods are factors, and this study (The Lancet, 2019) for example suggests reducing red meat mainly, but speculatively animal protein in general.

There’s nothing correcting for fibre that I can find though. Do you know where I can read the Oxford study to which you refer?

But the reason I posted here was to ask about this in relation to weight training. What I’d like to know is if there’s a problem with reducing your protein intake to the level given by WHO and other medical institutions. Much of the research I read points to a Mediterranean style diet (the real one, not "pour olive oil over everything) which essentially meets all the criteria of a healthy diet as per your articles except much less animal products. Would say 0.8-1.0 g/kg/day have a significant negative impact on training?

(I currently eat about 250g a day so this would be a big change for me.)

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The EPIC-Oxford trials has produced probably > 100 publications. I’d start here for some interesting stuff: High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition–Oxford study - PMC

I don’t really care if people consume animal products or not, provided they get enough protein, calories, etc. (though most folks eat too many calories as it were). Yes, I think consuming significantly less than 1.6g/kg/day of protein (probably anything < 1.2-1.4) would have a negative impact on training outcomes.

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