HomeNutrition ExpertsMark Hyman

Learning from Mark Hyman

The doctor who proved that food is information—and the wrong information makes you sick


The Story

For decades, doctors treated diseases like diabetes, heart disease, and obesity as separate problems requiring separate pills. Mark Hyman saw something different.

As a practicing physician, Hyman kept noticing the same pattern: patients with diabetes also had high blood pressure, joint pain, brain fog, and fatigue. What if these weren't separate diseases—but symptoms of the same underlying problem?

His answer changed how millions of people think about food: what you eat doesn't just give you calories—it gives your body instructions.

The wrong foods tell your body to store fat, create inflammation, and age faster. The right foods tell it to burn fat, reduce inflammation, and repair itself. This isn't a metaphor—it's biology.


Who is Mark Hyman?

CredentialDetail
RoleHead of Strategy and Innovation, Cleveland Clinic Center for Functional Medicine
Known For"Functional Medicine" approach, the Pegan diet, treating root causes over symptoms
Books14 New York Times bestsellers including The Blood Sugar Solution, Food Fix, and Young Forever
RecognitionAdvisor to the Clinton Foundation Health Matters Initiative, ten-time #1 New York Times bestselling author

Hyman is one of the most influential voices in nutrition because he practices what he preaches—at one of the world's most respected medical institutions, with thousands of patients.


What ISP Students Learn

Lesson 1: Food Is Information, Not Just Fuel

"Food is not just calories. Food is information that controls every aspect of your biology."

Most people think of food as energy: eat more, gain weight; eat less, lose weight. Hyman argues this misses the point entirely.

Every food you eat contains molecules that interact with your genes, hormones, and gut bacteria. A donut and a sweet potato might have similar calories—but they send completely different signals to your body.

The donut tells your body: spike blood sugar, store fat, create inflammation.

The sweet potato tells your body: release energy slowly, feed gut bacteria, reduce inflammation.

What this means for young athletes: The food you eat today is literally programming your body for tomorrow's performance. Two athletes eating the same calories can have completely different results based on food quality.


Lesson 2: Your Gut Is Your Second Brain

"Your gut is not just where food is digested—it's the control center for your entire body."

Hyman was an early advocate for understanding the gut microbiome—the trillions of bacteria living in your digestive system. These bacteria:

  • Help digest food and absorb nutrients
  • Produce neurotransmitters that affect your mood
  • Train your immune system
  • Influence whether you store fat or burn it

When your gut bacteria are healthy and diverse, everything works better. When they're damaged (by processed foods, antibiotics, or stress), problems cascade throughout your body.

What this means for young athletes: Your gut health affects your energy, recovery, mental clarity, and even injury risk. Eating fiber-rich plants and fermented foods feeds the good bacteria.


Lesson 3: The Pegan Diet—Taking the Best of Both Worlds

Hyman noticed that two of the most popular diet tribes—Paleo (eat like a caveman) and Vegan (no animal products)—were arguing past each other. Both had valid points:

  • Paleo: Avoid processed foods, refined sugars, and industrial seed oils
  • Vegan: Eat more plants, reduce environmental impact

So he created the "Pegan" diet—a framework that takes the best of both:

Pegan PrincipleWhat It Means
75% plantsVegetables should dominate your plate
Quality proteinSmall amounts of high-quality meat, fish, or eggs as a "condiment"
Healthy fatsAvocados, nuts, olive oil—not industrial seed oils
No refined carbsSkip the white bread, pasta, and sugar
No dairyMost people do better without it

What this means for young athletes: You don't need to pick a diet "team." Focus on what works: lots of vegetables, quality protein, good fats, minimal processed junk.


Lesson 4: Sugar Is the Real Enemy (Not Fat)

For 50 years, Americans were told to avoid fat. Hyman argues this was wrong—and disastrous.

When food companies removed fat, they replaced it with sugar to maintain taste. The result? Obesity and diabetes exploded.

Hyman's position: healthy fats (from avocados, nuts, olive oil, fatty fish) are essential for brain function, hormone production, and feeling full. Sugar and refined carbs are the real problem—they spike blood sugar, create cravings, and drive inflammation.

"Fat doesn't make you fat. Sugar makes you fat."

What this means for young athletes: Don't fear healthy fats. Fear the hidden sugars in sports drinks, protein bars, and "healthy" cereals.


Key Takeaways

LessonOne-Liner
Food is informationWhat you eat programs your biology—choose your code wisely
Gut health mattersYour digestive system affects your brain, immune system, and performance
The Pegan approachLots of plants, quality protein, good fats, no processed junk
Sugar is the problemHealthy fats are essential; refined carbs and sugar cause the damage

How This Shows Up at ISP

Mark Hyman's principles inform the Bio Skill Tree in MyPath:

  • Fueling Consistency teaches students to see food as daily instructions for their body
  • Gut Health challenges encourage fermented foods, fiber diversity, and reducing processed foods
  • The "No Added Sugar Week" challenge helps students recognize hidden sugars and experience life without blood sugar spikes

When ISP students learn about inflammation, blood sugar, or gut health, they're learning the same concepts Hyman teaches at the Cleveland Clinic—just translated for athletes.


The Controversy

Hyman is not without critics. Some doctors argue that:

  • The "functional medicine" approach isn't always backed by rigorous clinical trials
  • Food elimination diets (like removing dairy) aren't necessary for everyone
  • His supplement recommendations go beyond basic nutrition

ISP's approach: We teach the principles that are widely agreed upon (whole foods over processed, gut health matters, sugar is problematic) while encouraging students to think critically about any health claim.


Learn More


"The body is not a collection of separate organs. It's a single, interconnected system—and food is the code that runs it."


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