The 4-Hour Body: Can You Actually Live Forever?

Tim opens this chapter with a promise: it will be the shortest chapter on life-extension ever written. He keeps that promise. But what’s packed in here is surprisingly practical.

It starts with two monkeys.

Two Monkeys, One Diet

Canto and Owen are rhesus monkeys at the University of Wisconsin. Nearly identical, except Canto eats 30% fewer calories than normal. He’s been on the monkey version of Weight Watchers for over 20 years. Owen eats whatever he wants.

The results seem obvious. In the “eat whatever” group, 37% have died from age-related causes. In the calorie-restricted group, the death rate is almost two-thirds lower. Case closed, right? Time to cancel dinner forever?

Not so fast.

A New York Times writer named Roger Cohen looked at the same two monkeys and described what nobody in the lab was mentioning. Canto looked drawn, miserable, mouth hanging open, eyes blank. Owen looked like a happy guy who just finished a great steak and a glass of wine. Eyes twinkling. Skin glowing. Relaxed.

Cohen’s conclusion was blunt: living to 120 holds zero appeal if you look and feel like Canto. He’d bet on Owen outliving the miserable dieter in the end.

Tim agrees with this take. And that sets up the real question of the chapter: how do you increase the length of your life without destroying the quality of it?

The Fancy Options (That Tim Avoids)

There’s a short list of therapies that could, in theory, get you to 200:

• Resveratrol - extends lifespan in nearly every species tested
• Rapamycin - an immunosuppressant that induces autophagy (cellular cleanup)
• Alzheimer’s vaccines
• Stem cell therapies

Tim lists them. Then says he’s avoiding all of them.

His reasoning: these are global therapies with broad molecular effects, and we don’t have long-term human data. Resveratrol works in lab animals, but it also blocks or activates estrogen receptors. Could that mess with hormonal feedback loops over decades? Nobody knows. Telomerase activators like TA-65 extend your chromosomal countdown clocks (telomeres), but could they also cause cancer by amplifying cell replication? Maybe. And TA-65 costs $15,000 per year for that uncertainty.

When the science can’t guarantee one outcome or another, Tim passes.

What Tim Actually Does

Instead of the fancy stuff, he picked three protocols. All cheap. All low-risk. And all of them have side benefits even if the life-extension angle turns out to be wrong.

1. Creatine Monohydrate ($20/month)

Yes, the same creatine bodybuilders have been using since the 1990s. Turns out it’s now a candidate for preventing Alzheimer’s, Parkinson’s, and Huntington’s disease. Nearly 20 years of published human research backs its safety.

Tim has family history of Alzheimer’s and Parkinson’s on both sides. So he takes 5-10 grams per day for two weeks, every two months. He tracks blood markers - liver enzymes, BUN, kidney function - to catch any problems early. Complications are rare, but he watches anyway.

2. Intermittent Fasting and Protein Cycling (Free)

Remember miserable Canto and his permanent diet? What if he only needed to fast sometimes?

Turns out you can match or beat the life-extension effects of constant caloric restriction with intermittent fasting. Even if you eat double the calories during your “on” periods. No net calorie reduction for the week.

Tim describes three popular approaches:

Fast-5: Fast for 19 hours starting at bedtime, eat normally for 5 hours. Good for weight loss (about a pound per week starting week three). But some research says the fasting benefits only work when you eat during daylight hours, so this one might be better for fat loss than longevity.

ADCR (Alternate Day Caloric Restriction): Cut calories 50-80% every other day. Studies showed improved insulin sensitivity and even reduced asthma symptoms after just two weeks.

Protein Cycling: This is the interesting one. Dr. Ron Mignery suggests that just one day per week of restricting protein to under 5% of calories can produce effects similar to long-term caloric restriction. The idea is that your body doesn’t panic when carbs or total calories drop - there are no essential carbs. But when essential amino acids like lysine disappear even briefly, your cells flip a survival switch. That switch triggers autophagy - basically cellular housekeeping where damaged proteins get cleared out. If you clear junk faster than it builds up, you slow aging.

What does Tim actually do? He eats an early dinner on Friday around 6 PM. Then he fasts. Around 10 AM Saturday (16 hours later), he eats a cup of spinach with vinegar, a slice of sourdough toast with lots of butter, and a glass of grapefruit juice. After noon, he goes into full cheat-day mode. That’s it. One brief low-protein window per week.

3. Donating Blood (Free)

This one sounds medieval. Bloodletting. But the science behind it is about iron.

Excess iron in your body helps produce free radicals, which play a role in aging. Pre-menopausal women lose iron regularly through menstruation. Post-menopausal women suddenly have heart attack rates similar to men. The theory: it’s the iron buildup.

Dr. Tom Perls, who runs the New England Centenarian Study (the world’s largest study of people who live past 100), donates blood every eight weeks specifically to keep his iron low. He believes less iron means slower aging.

There’s solid research backing this up. Iron reduction through blood donation has been shown to improve insulin sensitivity and reduce cancer-specific and all-cause death rates. High iron stores correlate with more heart attacks in healthy men.

Tim targets blood ferritin levels of 50 mg/dL, achievable with 1-4 donations spaced two months apart. Bonus tip: drink coffee an hour before donating and request a double plasma donation to increase removal of pesticides and environmental toxins stored in fat.

Even if the life-extension doesn’t pan out, you’re saving someone’s life with every donation. Hard to argue with that.

The Big Idea

Tim also mentions Alcor - the cryonics facility in Arizona where you can store your body (or just your head, like Ted Williams allegedly did) in case technology catches up later. And Ray Kurzweil’s book Transcend, which argues you just need to survive the next 20 years to benefit from DNA reprogramming and cell-repairing nanobots.

But the real point of the chapter is simpler than cryonics or nanobots.

Hans Christian Andersen wrote: “Just living is not enough. One must have sunshine, freedom, and a little flower.”

Tim’s message is the same. A life of constant denial is not freedom. The greatest rewards come from a good life, not just a long life. That probably includes some red wine, a few cheesecakes, and - as Tim puts it - perhaps even an ejaculation or two.

The three cheap protocols? They’re insurance. Low-cost, low-effort, low-risk things you do on the side while actually enjoying your life. That’s the whole philosophy. Live well first. Then hedge your bets with creatine, occasional fasting, and a blood donation every couple of months.

Not a bad deal.

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Next: Self-Experimentation and Spotting Bad Science

This is part of my 4-Hour Body retelling series. New posts every Saturday.