Now Available

The Metabolic Equation

Your Body's Variables, Your Life's Solution

A comprehensive guide to understanding why 88% of Americans are metabolically sick - and exactly what you can do about it.

The Metabolic Equation cover

The Problem Nobody's Talking About

88% of Americans are metabolically unhealthy
60% have at least one chronic disease
42% are clinically obese

You've been told to eat less and exercise more. You've been told fat makes you fat. You've been told cholesterol causes heart disease. You've been told to use "heart-healthy" vegetable oils.

You've been lied to.

For 60 years, the official dietary guidelines have been based on flawed science, corporate influence, and academic stubbornness. The result? An epidemic of obesity, diabetes, heart disease, and dementia that's getting worse every year.

What's Inside The Book

26 chapters covering every variable in your metabolic equation.

Part I: Understanding the Crisis

  • The epidemic nobody talks about
  • How we got here: 60 years of bad science
  • The lie on your plate: seed oils
  • The cholesterol myth debunked
  • Sugar and insulin: the real culprits

Part II: The Variables

  • Insulin: your master hormone
  • Food quality: beyond macros
  • Omega ratios: the inflammation equation
  • Protein: building blocks of health
  • Meal timing and fasting
  • The exercise paradox

Part III: The Hidden Factors

  • Sleep: the free miracle drug
  • Stress and cortisol
  • Gut health: your second brain
  • Minerals most people lack
  • Environmental toxins
  • Hormones and aging

Part IV: Taking Action

  • Your 4-week reset plan
  • Lab tests that actually matter
  • Working with (or around) your doctor
  • Building sustainable habits
  • Troubleshooting plateaus
  • Your lifelong equation

Chapters 21-26: The Final Variables

The closing chapters turn principles into execution, with practical guidance for training, metrics, rhythm, long-term maintenance, and risk factors most books ignore.

Chapter 21

The Exercise Starter Program

This chapter reframes exercise as metabolic medicine, showing how movement improves insulin sensitivity and mitochondrial function beyond calorie burn.

Chapter 22

Know Your Numbers

This chapter explains which metabolic labs actually matter, why routine physicals miss early dysfunction, and how to track real improvement.

Chapter 23

The Metabolic Rhythm

This chapter argues that timing is a key variable, where meal timing, sleep, and recovery windows can significantly alter outcomes.

Chapter 24

The Metabolic Quarter and Beyond

This chapter maps expected progress over the first quarter and lays out a framework for sustaining results over years, not weeks.

Chapter 25

Alcohol: The Metabolic Truth About America's Favorite Poison

This chapter details how alcohol disrupts fat oxidation, liver function, sleep architecture, and food decision-making during metabolic repair.

Chapter 26

Cannabis and Your Mitochondria

This chapter examines cannabis through a metabolic lens, focusing on mitochondrial energy systems and long-term performance implications.

WK

About the Author

William Kastner isn't a doctor, a nutritionist, or a fitness influencer. He's a father, a husband, and someone who got fed up with watching the people he loves get sicker while following official health advice.

After years of research - reading scientific papers, following the work of physicians who challenge conventional wisdom, and experimenting on himself - William wrote the book he wished someone had given him 20 years ago.

"I wrote this for my wife, my kids, my friends. I wrote it for everyone who's been told to eat less and move more while watching their health decline. I wrote it because the truth is out there, but it's buried under decades of bad science and corporate propaganda."

William lives in Napa, California with his wife Jennifer. Their daughter Haley contributed the vegan alternatives throughout the book.

What Readers Are Saying

"Finally, a book that explains WHY we're all so sick. William connects dots that most doctors never learned in medical school. This should be required reading."
- Michael R., Physician
"I've read dozens of diet books. This is different. It's not selling you a system - it's giving you the education to figure out what works for YOUR body."
- Sarah T., Health Coach
"I bought this for my parents. Dad was pre-diabetic and skeptical. Three months later, his A1C is normal and he's off two medications. The science convinced him."
- Jennifer M., Austin TX
"As a vegan, I appreciated that William didn't dismiss plant-based eating. The alternatives throughout the book make it actually doable."
- Priya K., California

Read the First Chapter Free

See for yourself why readers are calling this "the health book that finally makes sense."

Chapter 1: The Epidemic Nobody Talks About

Here's a number that should terrify you: 88%.

That's the percentage of American adults who are metabolically unhealthy. Not overweight - though most are that too. Metabolically unhealthy. Meaning their blood sugar, blood pressure, cholesterol, and waist circumference fall outside healthy ranges.

Only 12% of Americans - roughly one in eight - have optimal metabolic health.

Read that again. Let it sink in.

We're not talking about some fringe condition affecting a small population. We're talking about the overwhelming majority of an entire nation being physiologically broken. And it's getting worse, not better.

Continue reading...

Download Full Chapter (PDF)

Ready to Solve Your Equation?

Your health is the sum of many variables. Learn how to optimize each one.

Also available as audiobook and ebook.

Free Bonuses with Your Purchase

When you buy the book, you get free access to:

🍴

4-Week Meal Plan

Complete meal plans with shopping lists, prep guides, and vegan alternatives.

📝

Lab Test Guide

The tests you need, optimal ranges, and how to talk to your doctor about them.

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Community Access

Join the private community to ask questions and share your journey.

🍳

Recipe Database

Over 50 metabolically-healthy recipes, all under 30 minutes.

Frequently Asked Questions

No. While low-carb eating is part of the equation for most people, this book covers 19+ variables that affect your metabolism - including sleep, stress, omega ratios, mineral status, environmental toxins, and more. It's about understanding the complete picture, not just following another diet.

Yes. Every recipe includes a vegan alternative, developed by the author's daughter Haley who follows a plant-based diet. The core principles - eliminating seed oils, managing insulin, optimizing omega ratios - work regardless of whether you eat animal products.

This book questions dietary guidelines, not medicine. It encourages working with your doctor, getting proper lab tests, and using medication when needed. It's about adding information your doctor may not have, not replacing medical care.

The book is available in paperback, hardcover, Kindle ebook, and audiobook formats. All formats include access to the free online bonuses.

The book focuses on food first. Some supplements are discussed (like magnesium and omega-3s), but there are no required purchases or affiliate-linked products. Everything recommended is optional and widely available.