Quick note: I’m reopening a limited number of $149 Founding Customer spots for Life Story Magic, available through Wednesday.
I’ve been genuinely gratified by the response so far.
Life Story Magic also makes a meaningful gift. If you’d like, I can send a simple digital gift card for you to share with the recipient.
(Interviews themselves will be scheduled after January 1 — not before Christmas.)
See you at the gym
Over the past year, I dropped close to 50 pounds. (How did I gain 50 pounds to begin with? Slowly, then all at once.)
Anyway, here’s how I did the dropping part:
First—let’s put this upfront: I took Zepbound, a GLP-1 medication. Game-changing.
Next, I quit drinking alcohol. Well, mostly; nobody’s perfect. Also game-changing.
Finally, I got in the very consistent habit of going to the gym at least four days per week: Cardio, HIIT classes, and weight training.
It’s been a fantastic change all-around; I feel better, I think I look better, and all the blood work that I get done once a year has improved. But it turns out there might be another benefit that I had no idea about when I started.
In short, my brain age might have gone down, which is a good thing, at least according to new research from Washington University School of Medicine.
Muscle versus fat
The researchers used AI algorithms trained on MRI scans from 5,500 adults to determine each participant’s brain age.
On average, participants were 55 years old chronologically, but their brains looked slightly older — about 56 years old.
Those participants with more muscle tended to have younger-looking brains, while those with more hidden belly fat relative to their muscle had older-looking brains.
Moreover, the type of fat that they had—visceral or subcutaneous fat—played a direct role as well. For clarification:
Visceral fat is the fat tucked deep inside your abdomen, wrapped around your organs.
Subcutaneous fat is the pooled fat around your belly or other areas, which you can pinch under your skin.
A higher visceral fat-to-muscle ratio was associated with higher brain age, while subcutaneous fat showed no meaningful association with how old the brain appeared.
The connection between body composition and brain health makes sense.
Visceral fat is linked to a higher rate of diabetes, insulin resistance, pre-diabetic states, and high cholesterol, which creates inflammation throughout the body. Over time, that inflammation affects the brain.
“While it is commonly known that chronological aging translates to loss of muscle mass and increased hidden belly fat,” explained lead author Cyrus Raji, “this work shows that these health measures relate to brain aging itself. It shows muscle and fat mass quantified in the body are key reflectors of brain health, as tracked with brain aging.”
Better drugs in the future?
There’s an interesting wrinkle here for the millions of people taking GLP-1 medications.
While these drugs are effective at reducing body fat, they may also contribute to muscle loss, as Raji, an associate professor of radiology and neurology at Washington University, told NBC News in its reporting on this subject.
I knew that ahead of time, which is part of why I tripled down on my gym commitment (and protein intake) while losing weight. (I also built a small gym in my basement for days when I can’t get out on time.)
The findings, Raji suggested, could help design better medications—ones that target visceral fat more than subcutaneous fat while protecting muscle mass.
As he put it, “Losing fat—especially visceral fat—while preserving muscle volume would have the best benefit on brain aging and brain health.”
The basics still work
None of this requires an expensive full-body MRI or staying on a prescription medication forever. The basics still work:
Strength training at least twice a week, targeting all major muscle groups, with 10 to 15 different exercises doing 8 to 12 reps each.
Aerobic exercise is particularly effective at targeting visceral fat; aim for 150 minutes of moderate-intensity activity weekly.
Exercise physiologist Glenn Gaesser told NBC News that you get the biggest return on investment in those first 30 minutes of weekly exercise.
Bottom line: The visceral fat you lose and the muscle you build today might be protecting the brain you need tomorrow. That’s worth showing up for.
7 other things
Horror over the weekend: ‘We Were Just Sitting Ducks.’ How the Chaos Unfolded on Bondi Beach. People hid under counters and shielded their children as gunmen attacked Hanukkah celebrations in Australia, killing at least 15 people. Prime Minister Anthony Albanese said it was clear the gunmen were targeting the Jewish event as an act of antisemitism, and that it was driven by ideology that is an “extreme perversion of Islam.” (WSJ)
I think most people know this, but: A son of the director Rob Reiner who is being held in his parents’ murders argued with his father at a holiday party the night before the couple’s bodies were discovered on Sunday, according to a person who attended the gathering. The son, Nick Reiner, 32, was arrested on Sunday night and being held in a Los Angeles County jail without bail, the police said. Rob Reiner and his wife, Michele Singer Reiner, were found dead in their home in the upscale Brentwood neighborhood of Los Angeles on Sunday afternoon. Also, people might also already know what President Trump had to say about Rob Reiner afterward, but just in case, here’s a link. (NYT; Truth Social)
I hate that the first three stories are about violence, but here’s the final one of the day. A manhunt is underway after two people were killed and nine others were wounded in a shooting at Brown University in Providence, Rhode Island, on Saturday. Officials released new photos and videos of a person of interest this evening. A man detained over the weekend was released because the evidence no longer supported holding him, officials said. One of the victims was Ella Cook, vice president of the Brown College Republicans chapter. The other was Mukhammad Aziz Umurzokov, from Uzbekistan, in central Asia. (NBC News)
Elon Musk just took another giant leap toward becoming the world’s first trillionaire. Earlier this month, Musk’s rocket maker SpaceX launched a tender offer valuing the firm at $800 billion, up from $400 billion in August. That boosts the fortune of Musk, who owns an estimated 42% of SpaceX, by $168 billion to an estimated $677 billion as of 12 p.m. Eastern Monday. Musk is now the first person ever worth $600 billion or more. No one else has ever been worth $500 billion. (Forbes)
MacKenzie Scott has given $26B to nonprofits since 2019. Here’s what she supported in 2025. (The Washington Post)
A JetBlue passenger jet bound for New York took evasive action to avoid a mid-air collision with a U.S. Air Force tanker plane near Venezuela, a pilot said in an air traffic control recording. JetBlue Flight 1112 had departed the Caribbean nation of Curacao and was flying about 40 miles off the coast of Venezuela when the Airbus A320 reported encountering the Air Force jet, which did not have its transponder activated, according to the recording captured by liveatc.net. (Reuters; YouTube)
Where people moved to (and from) in 2025. (Axios)
Thanks for reading. Photo by Centre for Ageing Better on Unsplash. I wrote about some of this at Inc.com. See you in the comments!
Love the main article topic share and congratulations Bill for prioritizing and increasing your healthspan!!
Very disappointed in seeing a Truth Social link here today.