Did you know that the 37 trillion cells in your body play a critical role in maintaining your health and vitality each day? In Good Energy, Dr. Casey Means, a former surgeon turned metabolic health advocate, challenges the conventional approach to healthcare. She explains how optimizing cellular energy, or “Good Energy,” can be the key to preventing chronic diseases and living a healthier life.
In this free Good Energy summary, you’ll explore the science of your body at the cellular level and gain practical, sustainable strategies for achieving optimal health.
The Dangers of Metabolic Dysfunction
Dr. Means’ journey began in her surgical residency, where she witnessed the shortcomings of modern healthcare. Despite increased healthcare spending, chronic diseases continue to rise:
- 6 out of 10 adults in the U.S. live with a chronic illness.
- 40% of teens are overweight or obese, with nearly 30% being prediabetic.
After years of seeing patient health worsen despite surgeries and medical interventions, Dr. Means decided to investigate the root cause of rising chronic illnesses. She found a common root cause behind most modern diseases—metabolic dysfunction.
Good Energy vs Bad Energy
Metabolic health is how well your cells generate energy to keep your body functioning optimally. When cells work efficiently—a state Dr. Casey Means calls Good Energy—your body thrives, keeping you healthy, energized, and mentally sharp.
But when cells can’t generate energy properly, Bad Energy sets in, leading to metabolic disease.
Modern lifestyles disrupt the natural systems our bodies evolved to rely on, with factors like ultra-processed foods, sleep deprivation, artificial light, and environmental toxins triggering this dysfunction. This mismatch can lead to chronic diseases such as diabetes, heart disease, and cancer.
The Vicious Cycle Behind Modern Diseases
At the heart of metabolic dysfunction is mitochondrial health. Mitochondria, the powerhouses of our cells, convert food into energy. Specifically, it converts food energy into adenosine triphosphate (ATP), the energy currency that powers all cellular functions. ATP is required for vital cellular functions like protein synthesis, metabolism, cell signaling, and waste management. When mitochondria are damaged, a harmful cycle begins, affecting all aspects of health:
- Mitochondrial Dysfunction: Damaged mitochondria produce less energy and release distress signals, which can trigger insulin resistance and elevate blood sugar levels.
- Chronic Inflammation: The immune system interprets these signals as threats, leading to persistent inflammation that damages tissues and organs.
- Oxidative Stress: Excess free radicals overwhelm the body’s defenses, accelerating aging and disease progression.
Instead of treating symptoms in isolation, we should address the shared root cause—Bad Energy—to prevent minor health issues (like fatigue and erectil dysfunction) from escalating into chronic conditions (such as stroke, cancer, heart disease, or other chronic issues). Fortunately, you can restore metabolic health with small, consistent changes in your daily life.
How to Create Good Energy & Avoid Bad Energy
It is possible to restore metabolic health through small, consistent lifestyle changes. Dr. Casey Means explains (in great detail) how various lifestyle and environmental factors are hurting our cellular health to cause short-term discomfort and long-term diseases. These include: harmful inputs (e.g. excess sugar, unhealthy fats, lack of key micronutrients, medications/drugs), imbalanced gut microbiome, disrupted biological rhythms (e.g. sleep deprivation, artificial light, erratic meal timings), environmental and lifestyle stressors (e.g. physical inactivity, lack of extreme temperature variation, chronic stress, environmental toxins).
She shares a range of practical habits and actions that can be easily incorporated into modern life. Here’s a quick visual summary of the key health pillars addressed:
Listen to Your Body Through Biomarkers
Your body provides early warning signs of cellular dysfunction through measurable indicators like blood sugar, triglycerides, and waist circumference. By tracking these biomarkers, you can spot issues before they escalate. For example, optimal blood sugar levels range from 70–85 mg/dL, while 100–125 mg/dL signals prediabetes, and levels above 126 mg/dL indicate diabetes. Check out our full 22-page summary for details all the important biomarkers to monitor, how to interpret them, and how to aim for optimal ranges—not just “normal” levels.
Adopt Good Energy Eating Principles
Food isn’t just fuel for the body, but a set of molecules that interact with our cells to affect cellular health and energy levels. Nutrient-dense, whole foods support cell renewal, regulate energy production, and promote overall well-being, while ultra-processed foods disrupt these processes and contribute to chronic diseases. In our full Good Energy summary, you’ll find 6 essential eating principles to boost metabolic health, including a list of must-have nutrient-rich foods and the “Unholy Trinity” of ultra-processed foods to avoid (e.g. refined seed oils, grains, and sugars).
Respect Your Biological Clock
Humans are biologically designed to move and eat during the day and rest at night. Disrupting this natural circadian rhythm impairs energy production and overall metabolic health. The book includes detailed, practical strategies to help you align your lifestyle with your biological clock. In our full summary, you’ll learn how to manage light exposure, adopt healthy sleep patterns, and optimize meal timings to minimize metabolic issues and maximize health benefits.
Restore Movement and Healthy Environments
Sedentary lifestyles, controlled indoor climates, and exposure to harmful chemicals weaken metabolic health. Regular movement boosts antioxidant defenses, reduces free radical damage, and improves insulin sensitivity, which helps regulate blood sugar and prevent glucose spikes. In our complete 22-page Good Energy summary, you’ll find actionable advice on staying active, using cold and heat exposure to improve your body’s resistance, and creating a healthier environment for better well-being.
Manage Stress and Anxiety
Since the brain consumes 20% of the body’s total energy, it needs a steady supply of energy for focus, emotional stability, and resilience, all of which requires proper mitochondrial function. With Good Energy, we can prevent blood sugar crashes, support neuroplasticity, and help the brain adapt and thrive.
Chronic stress, on the other hand, disrupts mitochondrial function, leading to Bad Energy and worsening mental health. Apply the strategies outlined in our full summary to manage stress, cultivate resilience, and overcome fear.
Getting the Most from Good Energy
To help us get started, Dr. Means selected 25 of the most impactful Good Energy strategies and habits above and combined them into a practical four-week plan. This plan focuses on building habits like improving sleep quality, adopting a healthy diet, managing light exposure, and minimizing toxin exposure. By the end of the 4 weeks, you’ll have integrated these habits, experienced a mindset shift, and gained significant health benefits.
If you’re ready to start your health journey, check out our full summary bundle for details of the Good Energy plan, along with more insights on cellular energy and overall health. This includes an infographic, a 22-page text summary, and a 34-minute audio summary.
The is one of the most comprehensive health books on metabolic and cellular health , with in-depth discussions on how a wide range of food, movement, and environmental factors impact cellular functions and metabolic functions. Dr. Means combines scientific research with practical recommendations, including meal ideas, health tips, and snack suggestions. For more details and valuable resources, purchase the book here or visit caseymeans.com.
For more resources on achieving optimal health, feel free to check out our summaries for:
- Prevent and Reverse Heart Disease: Discover why/how a plant-based, oil-free diet can prevent the progression of coronary heart disease and other chronic diseases.
- Lifespan: Understand the science of aging, and how it can be slowed and even reversed just like any disease.
- The Story of the Human Body: Learn more about the human body from an evolutionary perspective, for a deeper understanding of the evolutionary mismatch from the modern lifestyle and environment.
- Why We Sleep: Learn the importance and the benefits of sleep and the strategies to achieving quality sleep.
Who Should Read This Book
• Professionals, researchers, and policy-makers in the medical and health industries.
• Anyone wants to improve their health and vitality, or understand more about the human body and cellular health.
About the Author of Good Energy
Good Energy: The Surprising Connection Between Metabolism and Limitless Health was written by Dr. Casey Means, M.D. She is a Stanford-trained physician, biomedical researcher, and entrepreneur dedicated to revolutionizing metabolic health. She co-founded Levels, a health technology company focused on personalized nutrition and metabolic fitness. Dr. Means is also a sought-after speaker and writer, contributing to leading publications on topics ranging from lifestyle medicine to the science of habit formation.
Good Energy Quotes
“My hope for this book is to change your life by enabling you to feel better today and prevent disease tomorrow.”
“Having Good Energy is the core underlying physiological function that, more than any other process in your body, determines your predilection to great mental and physical health or to poor health and disease.”
“Each of our thirty-seven trillion cells is like a little city—continually bustling with action, transactions, and production—and contained by its cell membrane.”
“Every institution that impacts your health makes more money when you are sick and less when you are healthy—from hospitals to pharma to medical schools, and even insurance companies.”
“We have so normalized what Dr. Mark Hyman refers to as ‘FLC’ (feel like crap) syndrome that many of us can’t even imagine what it could feel like to be symptom-free.”
“High blood pressure is the most common preventable risk factor for cardiovascular diseases.”
“We are entering the era of bio-observability: more readily available blood tests and real-time sensors filtered through AI analysis to give us a highly personalized understanding of our bodies and a personalized plan to meet each body’s needs with daily choices. This can’t be crystallized in a fifteen-minute doctor’s visit.”
“By avoiding added sugar, industrial seed, and vegetable oils, and processed grains, you avoid almost every ultra-processed food. And by doing this, you also avoid the innumerable additives in ultra-processed foods that directly damage us.”
“You will either pay for healthy food up front or you will pay for preventable medical issues and lost productivity in the future.”
“Prolonged sedentary time is associated with bad health outcomes, regardless of physical activity. Sitting itself is the monster, no matter whether you exercise.”
“Practicing simple Good Energy habits is an act of rebellion…By engaging with these simple habits, you can thrive and minimize your risk for so many of the conditions related to suboptimal cellular energy production.”
Click here to download the Good Energy infographic & summary