BRAINBITES
WEEK OF SEP 25–OCT 1, 2026 · ISSUE 28
BRAINBITES — Your weekly health, fitness, and longevity digest. Five minutes that cover the highest-signal podcasts and science before they hit the mainstream.
This week: Lloyd Klickstein told Peter Attia that building one new drug takes as many people as building the Burj Khalifa, and the drug in question is one that protects muscle. We paired it with the trial behind it, then borrowed Kelly Starrett's floor for a test that costs nothing. Plus Michael Pollan on the bacteria with a say in your mood, a JNNP paper on the MIND diet and brain aging, and the shortest tool on Huberman's focus list.
From: The Peter Attia Drive · Nature Medicine · FoundMyFitness · Huberman Lab · JNNP
🔢 92% — how much of the weight lost was fat, once a muscle drug joined the party
🎙️ Lloyd Klickstein on the skyscraper behind every pill
⚡ Action: the floor test, two minutes, one rug
📰 News Bits: Pollan on the microbes with a vote · the MIND diet and 2.5 years · a 13-minute focus tool
GM.
Ninety-two. That is the share of lost weight that was fat when a trial added a muscle-protecting antibody to semaglutide, against about seventy-two without it. Which raises the question this issue answers for free: how is yours holding up, and can you check with nothing but a rug?
⏱ ~5 min read
🧠 THE MUSCLE QUESTION
Keeping what you have is cheaper than buying it back.
Issue 27 closed with Andy Galpin asking you to test before you train. This week is the sequel: a drug developer explains why muscle is worth a billion-dollar bet, and a 2,002-person study explains how to check your own for the price of a clear patch of floor.
🔢 THE VITAL SIGN · OBESITY MEDICINE / BODY COMPOSITION
92%
The share of weight lost that was fat when a muscle-protecting antibody joined semaglutide. On semaglutide alone it was about 72%.
The BELIEVE trial followed 507 adults with obesity for 72 weeks on semaglutide, an antibody called bimagrumab that blocks the brakes on muscle growth, or both. Heymsfield and colleagues published it in Nature Medicine this August.
Semaglutide alone took off 15.7% of body weight, and lean mass fell 7.4%. Adding bimagrumab took off 22.1%, and lean mass fell 2.9%. Bimagrumab by itself raised lean mass 2.5%.
What it means: on semaglutide alone, a bit over a quarter of the weight lost was not fat. Two cautions. Lean mass is more than muscle, and the drug is investigational, given by infusion, with muscle spasms, acne and a temporary rise in LDL on the side effects list. Nobody can order it, which is why the free test further down matters more.
🎙️ THE EPISODE · DRUG DEVELOPMENT / MUSCLE
Every pill is a skyscraper.
Lloyd Klickstein on what it takes to bring one medicine to patients, and why he bet on muscle.
Lloyd Klickstein, M.D., Ph.D. · The Peter Attia Drive #409 · 28 September 2026
Klickstein ran translational medicine at Novartis, then co-founded Versanis Bio, the company behind the trial above and acquired by Eli Lilly for up to $1.925 billion. He is an excellent guide and an interested one, so keep both in mind.
A skyscraper, not a pill.
His line: making a new drug used by many people "takes longer, is more expensive, and takes as many people as building the biggest skyscraper in the world. Think the Burj Khalifa." The episode walks the whole build in order, from patents and antibody engineering to animal tests, toxicology, manufacturing and the first human dose.
Pick a target you can measure.
He chose sarcopenia, age-related muscle loss, and the show notes flag measuring falls as part of that choice. Muscle on a scan is a means. Staying upright is the point, and a drug has to move that.
🎙️ Start at 1:59:30 (audio) for the bimagrumab-plus-semaglutide trial, told by the person who built it.
The practical takeaway.
The drug is years from your pharmacy, if it gets there. The muscle you already have is the part within reach, and the way to find out how it is doing is just below.
⚡ ACTION · CHECK THE CHASSIS
The floor test
Sitting down on the floor and getting back up uses leg strength, balance, hip and ankle mobility and the strength-to-weight ratio all at once. Kelly Starrett's FoundMyFitness episode this week lists floor sitting among its mobility tools, and there happens to be a scored version.
1. Clear a patch of floor next to a sofa. Go barefoot. Skip it if a knee, hip or balance problem makes this risky.
2. Start at 10 points. Lower yourself to sitting cross-legged without leaning on anything.
3. Stand back up the same way.
4. Subtract one point for each hand, knee, forearm or side of the leg you lean on, and half a point for a visible wobble.
5. Write the score down. Retest in a month.
In a Brazilian cohort of 2,002 adults aged 51 to 80, followed a median 6.3 years, 3.6% of those scoring 8 to 10 died, against 19.2% of those scoring 3 or less. Each extra point went with 21% better survival, after adjusting for age, sex and BMI. It is a marker, not a lever: the score reflects what is underneath it, and the people in the study were not a random sample of anyone.
Don't overthink it. This week, once, then do it again in a month.
📰 NEWS BITS
Michael Pollan: your microbes may have a say in your mood.
Pollan's two-hour tour of consciousness spends a stretch on the microbiome, arguing that gut bacteria make compounds that reach the nervous system, with the vagus nerve carrying the news up. It is an argument for taking the gut-brain axis seriously, not a result. His own habit of testing whether an idea is useful before believing it is the better takeaway.
— Huberman Lab, Michael Pollan, 28 September 2026
The MIND diet and 2.5 years of brain.
In 1,647 middle-aged and older Framingham Offspring participants scanned repeatedly between 1999 and 2019, every 3-point rise in MIND diet score went with slower grey-matter loss, equivalent to about 2.5 years of delayed brain aging. Berries and poultry sat on the good side, sweets and fried food on the other. Observational, so it shows who ages well, not what causes it.
— Journal of Neurology, Neurosurgery & Psychiatry, Chen, Yuan et al., 1 October 2026
Huberman's focus list has a 13-minute tool on it.
The Essentials edition on focus runs through noise, 90-minute work blocks, caffeine timing, cold, and supplements. The cheapest item is a daily 13-minute meditation, and the episode places it in its attention section. Pick one tool from a list of eight rather than adopting all of them.
— Huberman Lab Essentials, Dr. Andrew Huberman, 1 October 2026
P.S. Hit reply with your floor-test score. We will not judge anything below an 8. We will, however, quietly retest ourselves.
What did you think of today's BrainBite?
🧠🧠🧠🧠🧠 I tried the floor test. I have notes.
🧠🧠🧠 The skyscraper line is the one I'll repeat at dinner.
🧠 I read this sitting down. On a chair. Thank you.
We listen to every health podcast so you don't have to. Weekly. No noise.
Sit down on the floor. Stand back up. That was the whole experiment. See you next week.
