Take the two-week Tsimane Diet Challenge. It’s entirely free. You’ll learn something that’ll change how you eat and think about food—leading to lasting health improvements.

Housekeeping

• Arnold Schwarzenegger named Scarcity Brain one of his best books of 2023. Thanks, Arnold.
• Today’s post and its audio version are free to all, as are all Monday posts.
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If I’ve learned anything from my work, it’s that you usually have to go to the ends of the earth to get the best stuff.

Case in point: While reporting my book Scarcity Brain, I found myself in the middle of the Bolivian Amazon. I was sitting in a 30-foot long, 3-foot wide motorized canoe.

We’d been navigating deep into the jungle river for far too long. Eventually, we veered the boat to a sandy bank.

I’d taken this inconvenient trip—24 hours of flights, 12 hours of driving down cliffside roads, 6 hours in the canoe—because I’d stumbled upon a fascinating study.

The research suggested that a tribe in the most remote reaches of the Bolivian jungle had beaten the diseases most likely to kill you, me, and everyone we know.

But how they did it didn’t necessarily add up.

This post will dive into what I learned from the tribe. It revolves around what they eat.

It’s an introduction to a free two-week Tsimane Diet Challenge that’s open now. You can sign up for the challenge at the form on my homepage. Just click the button below and you’ll be on your way.

The challenge introduces you to what is arguably one of the healthiest ways of eating on earth.

The two-week Tsimane Diet Challenge will give you:

• The tools to eat like the Tsimane for two weeks.
• The skills you need to successfully complete the Tsimane Diet Challenge.
• Information about the origins of diet and why it’s so powerful.
• A dive into the psychology of diet change and how food impacts hunger and our rate of eating.
• Strategies to work the diet into your life so that it’s easy and seamless.
• Tactical answers to the most common questions about the diet.
• And much more …

All for free. Sign up for it here.

When you sign up, you’ll immediately get the first email. Then, over the next two weeks, you’ll get 10 more emails guiding you through the challenge.

Today’s post will be a quick rundown about the Tsimane, their diet in practice, the paradoxes of their diet, and how I view challenges as part of a long-term eating strategy.

The Tsimane: A Quick Primer

In short

The Tsimane are a small tribe of hunter-gatherer horticulturalists in the Bolivian Amazon.

The details

I’d traveled all that way to meet and live with the Tsimane tribe.

The Tsimane are a band of hunter-gatherer horticulturalists who live deep in the Bolivian Amazon.

In 2017, a team of international researchers from some of the world’s top institutions learned something groundbreaking about the tribe.

It all started when they noticed that no one from the tribe seemed to die of heart disease. It was a curious observation—because heart disease is the number one killer of people worldwide.

The average American, for example, has a roughly 50 percent chance of dying from heart disease. (Want to know the most sustainable way to avoid disease? Read The 2% Manifesto).

After that big observation, the scientists followed up with a formal study. And it was revelatory.

The Tsimane Heart Study

In short

The Tsimane were found to have the healthiest hearts in the world.

The details

A scientist named Michael Gurven led the study. He’s one of the world’s leading anthropologists.

Gurven’s team of doctors gathered nearly 1,000 Tsimane over 40. “We really wanted to delve into heart disease at a much more sophisticated level than just taking some blood pressure readings,” Gurven told me.

The scientists gathered tribe members and ran them downriver to a medical clinic to analyze their hearts with detailed CT scans.

• The scans revealed something wild: The Tsimane had the healthiest hearts ever recorded by science.

That bears repeating: The Tsimane had the healthiest hearts ever recorded by science.

Even the oldest among the tribe, people well past 70 years old, showed minimal evidence of heart plaque buildup. Tsimane hearts appeared, on average, 30 years younger than those of the average American.

Even wilder, the effects of their healthy hearts cascade upstream to their brains and downstream to their other major organs. One study found that aging Tsimane brains decrease in size 70 percent slower than the brains of Americans.

This means the Tsimane don’t seem to get dementia and Alzheimer’s (the fifth leading cause of death worldwide). Another study found that they don’t get diabetes and kidney diseases (the ninth leading cause of death). Even most cancers are rare.

Hell, the Tsimane even showed what’s called a slower “epigenetic aging rate.” That’s a detailed measurement of how our cells, tissues, and organ systems are aging. If there’s a fountain of youth, the Tsimane seem to be sipping from it.

Meanwhile, the average American is more likely to be sick than not. Six out of every ten of us have a chronic disease. Four out of ten have two or more. The Tsimane: 0 for 10. They suck at dying of the diseases that kill us.

Our heart disease numbers are particularly savage.

In America, cardiovascular disease kills one of us every 34 seconds. Even the young are at increasing risk. About 30 percent of all heart attack patients today are between 35 and 54 years old. Today 40 percent of all people who die before turning 70 die of cardiovascular disease. Exactly 44.7 percent of American women above age 20 have some grade of cardiovascular disease. In the US at the height of the pandemic, the malady killed 250 percent more people than did COVID-19.

(P.S. If you’re under 55, read this to learn about what’s even more likely to kill you—and how you can avoid it.)

But Gurven’s findings suggested that some of these diseases we consider an inevitable part of growing old aren’t. And it all goes back to what we eat.

The Tsimane Diet: In Practice

In short

The Tsimane eat foods that have just one ingredient.

The details

Research shows that the Tsimane eat about 152 different foods. But they don’t eat like you and me.

They eat very differently.

The Tsimane diet relies on a set of powerful single-ingredient foods.

It’s a simple idea, but today roughly 60 percent of what we eat is what scientists call “ultra-processed.”

Scientists define ultra-processed foods as “formulations mostly of cheap industrial sources of dietary energy and nutrients plus additives, using a series of processes and containing minimal Whole Foods.” I.e., Junk food.

They’re foods packed with all sorts of ingredients that ultimately lead us to overeat. Scientists know these ultra-processed foods have altered our health and performance in many ways—and in ways they have yet to discover.

And it’s quite shocking just how common these foods are—they make up 75 percent of our food supply. Even “diet foods” we might think of as healthy, like protein bars or keto meals, are ultra-processed.

Take what happened when I first decided to try the Tsimane diet after living with the Tsimane tribe. I entered my pantry and took stock. It held 127 different foods.

But just 15 were one-ingredient foods the Tsimane might eat—and I was counting canned vegetables.

Yet soon into the diet, I was sleeping better. My skin was clearer. My blood pressure and resting heart rate lower. My endurance and gym performance better. I was more focused and productive at work.

I just felt … better.

I also dropped from 180 pounds to 172 (even though weight loss wasn’t the goal).

The Tsimane Diet: Paradox and Specifics

In short

The Tsimane breaks many rules of fad diets. But it works.

The details

The thing I had trouble with, and why I took that most inconvenient trip down into the jungle, was this:

• What Gurven told me about Tsimane eating didn’t add up.

Name a diet, any popular diet of the last 50 years.

The Tsimane way of eating, somewhere in a day’s worth of meals, will give it the middle finger.

It’s not paleo, vegan, keto, plant-based, low-carb, Mediterranean-style, or any of the fads we were sold and told are the key to health, longevity, and a body you could put on a magazine cover.

They eat everything from meat to rice to corn to sugar to potatoes and more. For example, corn is off-limits in 9 of the 10 most recent best-selling diet books—and yet the Tsimane are healthier than any diet book author ever will be.

• The key: All the Tsimane foods have just one ingredient. The only processing is in the cooking.

For nearly all of time, people mostly ate like the Tsimane: simple foods that had one ingredient.

But in the 1970s, the global food system tipped to producing an abundance of exceedingly delicious foods. This delectable, pre-formulated food was everywhere, in mass quantities. (Learn how food corporations leveraged the most addictive behavior loop to compel us to eat more).

And we (over)ate it.

Meanwhile, here’s what an average day of Tsimane eating looks like. Everything the tribe eats comes from the surrounding jungle.

• They eat lean meat that they hunt, raise, and fish. Foods like Tapir, an Amazonian deer, chicken, and a range of fish from the rivers they live on.
• They eat various fruits and vegetables that naturally grow in their environment.
• They grow their own foods like rice, corn, plantains, sweet potatoes, and various vegetables in small gardens.

Their plates are usually composed like this:

• 50-70 percent carbohydrates like rice, plantains, or sweet potatoes.
• 15-25 percent lean protein like fish or game meat
• 15-25 percent vegetables and/or fruit

The challenge breaks down how the average person—i.e., you—can apply the approach to your modern life. It includes a grocery list, sample meal plans, recipes, etc.

The Tsimane Diet Challenge

In short

Challenges give us an extreme experience to learn from. We can then apply those learnings to our everyday approach.

The details

The point of the two weeks is to throw yourself into the fire. You’re adopting a lot of diet changes at once. It’s a challenge!

(Sign up through the form on my homepage by clicking the button below)

I don’t expect you to stay in the fire for the rest of your life (but kudos if you do).

Rather, I hope you learn something from your time in the fire. Research shows that humans learn best from more extreme experiences. It leads to deep learning.

The goal is to gain insights that change your eating strategies.

When the two weeks are up, you should take the best of the Tsimane diet and flow it into your “everyday” diet. Even if you take just one lesson or trick, you’ll be healthier.

Have fun, don’t die, eat well.

-Michael

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