The Wellness Brew - Issue 25

The official recommendation for protein hasn't meaningfully changed since the 1970s. It was set to answer a narrow question — how little can you get away with — and it's been repeated ever since as though it were a target. Newer research points somewhere considerably higher, and the gap between the two numbers is bigger than most people would guess.

But first, we filtered the noise — here's what's worth knowing this week.

The thymus sits behind your breastbone, trains your T cells in childhood, and shrinks steadily after puberty. Surgeons have long viewed it as unnecessary in adults and routinely remove it during heart surgery. A study out of Massachusetts General published in the New England Journal of Medicine compared 1,146 adults who had their thymus removed (thymectomy) against matched patients who had similar cardiothoracic surgery without it. Five years later, all-cause mortality was 8.1% in the thymectomy group versus 2.8% in controls, with roughly double the cancer risk. The thymectomy patients also produced fewer new T cells and showed higher inflammatory markers. This is observational, so it shows association rather than causation. Interesting nevertheless. — Kooshesh et al., New England Journal of Medicine, 2023.

Lifting weights makes you a more efficient runner late in a race

Running economy is how much oxygen you burn at a given pace, and it degrades over the course of a long run. That degradation is a big part of why marathons fall apart in the last hour. Researchers at Loughborough took 28 well-trained male runners, average 10K time of 39 minutes, and split them into two matched groups for 10 weeks. Both kept their running identical. One group added maximal strength and plyometric work twice a week. Then both ran 90 minutes at marathon-effort intensity with running economy measured every 15 minutes, followed by a high-intensity test to exhaustion. The strength group held their economy meaningfully better across the 90 minutes and lasted substantially longer on the fatigued performance test. It's only 28 participants and all male, so take it with a bit of a caveat. Still, it's the clearest evidence that time in the weight room pays off in the final miles. — Zanini et al., Medicine & Science in Sports & Exercise, 2025.

Tart cherry juice and sore muscles

A network meta-analysis in Frontiers in Nutrition compared eight plant-derived polyphenol supplements for recovery after hard exercise and found tart cherry had both the deepest evidence base, with 13 trials, and the most consistent results for reducing delayed onset muscle soreness. The compounds behind it are anthocyanins, the pigments that make the fruit dark red, which appear to blunt the inflammatory response to muscle damage. Two things worth knowing before you buy any. The benefit is specific to soreness rather than recovery across the board, so don't expect it to move strength recovery or blood markers much. And the researchers noted so much variation in product form, dose, and timing across trials that no standard protocol has been established. The practical version: unsweetened tart cherry juice, roughly 8 ounces, in the day or two around a hard session. Not the sweetened cocktail blends, which are mostly apple juice and added sugar. It's also the same thing we've recommended for sleep, so it does double duty. — Frontiers in Nutrition, 2026.

If you've ever looked up how much protein you need, you probably landed on the same number everyone lands on: 0.8 grams per kilogram of bodyweight. For a 180-pound person that works out to about 65 grams a day. Two chicken breasts and you're done.

That number comes from the Recommended Dietary Allowance, the official U.S. government guidance for nutrients. And it's worth knowing what it was actually built to do, because it isn't what most people assume.

The Recommended Dietary Allowance for protein was set to answer one question: what's the least amount a healthy adult can eat without developing a deficiency? [1]

That's a useful question. It's just not the one most of us are asking. Nobody reading this is trying to figure out how to barely avoid malnutrition. You want to know how much protein supports building muscle, keeping it as you age, recovering from training, and staying full between meals. Those are different questions with different answers.

The way the number was calculated also has some problems. It came from what researchers call nitrogen balance studies, where people eat carefully controlled experimental diets for weeks while scientists measure how much nitrogen goes in versus how much comes out. Protein is the only nutrient that contains meaningful nitrogen, so tracking it gives you a rough estimate of whether someone is breaking even. It's an indirect method, it's slow, and it can only really tell you where the break-even point sits. It can't tell you where you'd actually do best.

When researchers went back and reran the original numbers with better statistical methods, the estimated requirement came out higher: about 0.91 grams per kilogram, with a recommended intake closer to 1.0. [2] That's already 25% above the official figure, using the same data.

Over the last fifteen years, researchers developed a different approach. Rather than measuring nitrogen going in and out, they track a single amino acid using a harmless tracer and watch how much of it the body burns off. When you're short on protein, your body burns more of that amino acid as waste. When you have enough, the burning drops off. The point where it levels out is the requirement.

Worth separating two numbers here, because studies report both. The requirement is what the average person needs to break even. The safe intake is set higher, to cover people whose needs run above average, and that's what an official recommendation is supposed to be. The 0.8 figure is a safe-intake number, so that's the one to compare against.

In healthy young adults, the tracer method put the requirement at 0.93 grams per kilogram and the safe intake at 1.24. For a 180-pound person, that safe intake is about 101 grams a day, against the 65 grams official guidance suggests. [2]

In adults over 65, the safe intake came out around 1.2 grams per kilogram, roughly 40% above current recommendations. That's about 98 grams for a 180-pound person. The researchers also found no difference between men and women, or between younger and older adults, once you account for bodyweight. [3]

In endurance-trained athletes on a hard training day, the requirement was 1.65 and the recommended intake 1.83 grams per kilogram. For that same 180-pound person, roughly 150 grams. That's more than double the official number and well above the 1.2 to 1.4 typically recommended for athletes. [4]

Every time someone measures this with better tools, the answer comes back higher.

The best evidence on this comes from a 2018 analysis in the British Journal of Sports Medicine that pooled 49 studies covering 1,863 people who were lifting weights. Researchers looked for the point where eating more protein stopped producing more muscle.

They found it at 1.62 grams per kilogram per day, with a range of 1.03 to 2.20 depending on the individual. [5] Above roughly 1.6, the extra protein didn't add anything measurable to muscle gains in the pooled data.

Converting that to pounds, since that's how most of us think about bodyweight: 0.7 to 1.0 grams of protein per pound. For a 180-pound person, that's 125 to 180 grams a day. Compare that to the 65 grams the official guidance suggests.

Where you land in that range depends on what you're doing. Sedentary and not training, the lower end is fine. Lifting seriously, training most days, over 60, or eating in a calorie deficit, aim higher.

I personally target 1 gram per pound, which puts me at the top of that range. My reasoning: I train a lot and I've been training for a long time, and the research found the benefit of higher intakes is larger in people with more training experience. It's a number that’s easy to remember and hit without doing math at every meal. And protein is the hardest of the three macros to accidentally overeat, because it's the most filling by a wide margin. Most people who aim for 1 gram per pound end up somewhere around 0.8, which is right in the middle of where the evidence points anyway.

That's a practical target, not a magic number. If you're at 0.7 grams per pound and consistent, you're doing fine.

You'll see a lot of content suggesting women need a fundamentally different approach to protein. The research doesn't really support that.

When researchers measured protein requirements using the tracer method, they found no difference between men and women on a per-kilogram basis. [3] Differences in how men and women process protein exist, but they're small. [6]

What differs is bodyweight, not the multiplier. A 140-pound woman and a 200-pound man following the same guidance land at very different daily totals, because they're multiplying the same number by different bodyweights.

There's one useful clarification here. The muscle loss that comes with aging appears to be driven mostly by aging itself rather than by dropping estrogen levels. [6] Which means the answer for women in their fifties and sixties is the same answer as for men: eat enough protein and lift things.

If you want the technically optimal approach, it looks like this: roughly 0.3 grams per kilogram at each meal, spaced three to four hours apart, which works out to four or five meals per day. [7] Your body can only use so much protein for muscle building at once, so spreading it out theoretically beats loading it all into dinner.

Now the practical version, because almost nobody restructures their day around this and I'm not going to pretend otherwise.

Three meals with real protein at each one gets you most of the benefit. The place nearly everyone falls short is breakfast. A bagel, a bowl of cereal, a piece of toast, a smoothie made of fruit — these are the meals where people accidentally eat 5 grams of protein and then try to make up 60 grams at dinner, which doesn't work as well.

If you change one thing, make it breakfast. Eggs, Greek yogurt, cottage cheese, leftover meat from the night before, or a protein shake if you're in a hurry. Getting 30 to 40 grams into your first meal solves most of the distribution problem without any additional planning.

Total daily intake still matters more than perfect timing. A fourth feeding is a bonus, not a requirement.

This comes up every single time protein does, so let's deal with it.

There's no good evidence that a high-protein diet harms kidney function in healthy people. [8] Eating more protein does increase the rate at which your kidneys filter blood, and that observation is where the concern started. But the current understanding is that this is a normal adaptation to a higher workload, not damage.

The bone story went the same way. The old worry was that protein made blood more acidic and pulled calcium out of bone to compensate. That's largely been reversed. An analysis of more than 70,000 people in the UK Biobank found higher protein intake associated with higher bone mineral density, and protein supports bone through a growth factor called IGF-1. [9]

The one real caveat: if you already have chronic kidney disease, protein restriction is a legitimate part of treatment, and that's a conversation to have with your doctor rather than a newsletter. Kidney disease often goes undiagnosed, so if you have risk factors like diabetes or high blood pressure, it's worth knowing your numbers. For everyone else, this concern isn't supported.

The table below covers ten common foods at realistic serving sizes.

The bottom three are on there for a reason. Peanut butter, almonds, and quinoa all carry a reputation as protein foods, and all three are mostly something else. Two tablespoons of peanut butter gets you 8 grams of protein for 190 calories. Six ounces of chicken gets you 53 grams for 280 calories. That's the difference between a food that contains some protein and a food that delivers protein.

Knowing your protein number is the easy part. Standing in the grocery store trying to figure out which yogurt has 4 grams of added sugar and which has 14, or which ground beef is worth the extra three dollars, is where most of this falls apart.

That's what the Clean Grocery Guide is for. Brand-level recommendations across the categories that matter, with the ingredient red flags to check on the label.

The official guidance answers a question you're not asking. It tells you the minimum to avoid a deficiency, which is a low bar and was always meant to be one.

If what you actually want is to build muscle, keep it into your sixties and seventies, and recover from the work you're putting in, the range is 0.7 to 1.0 grams per pound of bodyweight. That's roughly double the official recommendation, it's well supported, and there's no evidence it does any harm.

We covered why muscle mass is a longevity marker back in Issue 17. Protein is how you feed it.

Three things you can do this week:

1. Do the math on your own number.
Multiply your bodyweight in pounds by 0.7 and by 1.0. That's your range. A 150-pound person is looking at 105 to 150 grams a day, a 200-pound person at 140 to 200. Land toward the top if you're lifting seriously, training most days, over 60, or eating in a deficit. Toward the bottom if you're mostly sedentary. Either way, it's likely well above what you're eating now.

2.  Fix breakfast first.
It's where nearly everyone comes up short, and it's the single change that closes most of the gap. Cereal, toast, a bagel, or a fruit smoothie will run you five to ten grams. Eggs, Greek yogurt, cottage cheese, leftover meat, or a shake gets you to 30 or 40. Do that one thing and the rest of the day stops needing to be perfect.

3. Build meals around the foods that actually deliver.
Chicken, beef, fish, eggs, Greek yogurt, cottage cheese, and lentils. Nut butters, nuts, and quinoa have protein in them, but they're mostly fat or carbohydrate, and counting on them is how people end up 40 grams short without knowing why.

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The Wellness Brew

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Disclaimer: The Wellness Brew is for informational purposes only and does not constitute medical advice. The content published here is not intended to diagnose, treat, cure, or prevent any disease or health condition. Always consult a qualified healthcare professional before making any changes to your diet, supplement routine, or lifestyle.