Book Excerpt: Dr. Molly Maloof on why energy is key to health

In this excerpt from her new book, Dr. Maloof explains why energy underlies good health, and how you can improve yours.


Dr. Molly Maloof is a Stanford lecturer, scientific advisor to several health-focused companies, and leading voice in metabolic health. In her new book, The Spark Factor, Molly unpacks the concept at the center of all health: energy. The book combines easy-to-understand, research-backed explanations of everything from mitochondria to the microbiome to CGMs and fasting with extensive practical advice for steps you can take now to improve your energy and overall health. In this excerpt from Chapter 1 of the book, Molly explains why energy underlies everything she talks about in the rest of the book (and so much of what we talk about on this site). 

The Spark Factor is available January 31; you can pre-order it here.

Energy Powers Life

While risk reduction and health maintenance are noble, it is time to move the focus and efforts toward positive health potential through improved physical, mental, and social capabilities. — Craig Becker and William Mcpeck (1)

Energy. It starts at the very beginning, when sperm meets egg. Scientists have captured on camera a fluorescent green zinc spark that flashes when an egg is fertilized.(2) Shortly after fertilization, the egg’s mitochondria begin to do the work of powering embryo development. Mitochondria are cellular organelles that act as the powerhouses of the cell. They store electrical charge like batteries. Keeping our spark bright throughout our lives is a function of how well our mitochondria are able to create, store, and use energy. Without enough energy, the body can’t do the work it needs to do. It can’t fuel life. The strength of your spark and your capacity for energy creation determine how healthy you are.

You may already have a sense about the general state of your spark. Do you feel energetic when you wake up in the morning? Throughout the day? Or do you run out of energy before the day is over? Do you live with pain? That can be a sign of energy deficiency. Do you glow with health? That is a sign of good energy capacity. Is your energy capacity sufficient for what your life, and the world, demands of you? Most of the women I treat would answer no.

In fact, one of the leading complaints in doctors’ offices today is fatigue. I’ve certainly noticed this shift, and so have my colleagues. Many people now consider it normal to be tired all the time, to be susceptible to viruses, and to have mood issues and exaggerated stress reactions, but none of this is normal. In my sickest patients with fatigue, I almost always see a similar pattern: a lifestyle that contradicts the principles of health and contributes to energy deficiency and immune system dysfunction. They get hit with a big stressful event, catch a nasty infection, and don’t recover to their previous energy level. They stay at a suboptimal level of health.

When you don’t have enough energy, you can feel it. Your brain can’t function optimally, your body can’t operate efficiently, and your life can feel more difficult, strenuous, and unsatisfying. If you aren’t sick yet, over time, sustained insufficient energy production will almost certainly result in illness. Energy is the primary underlying factor in both longevity (length of life) and healthspan (length of health). If you want to live long and enjoy your life right now and right up to the end, expanding your energy capacity to brighten your spark is where to put your focus.

Levels Member Experience:

Length of Life vs. Length of Health

Your healthspan is the portion of your life that you live without dis- ease or disability, during which you remain vital, mobile, engaged, and cognitively sharp, and it is a function of energy production. The more energy you produce in your cells, the better your body will function and the longer you will remain healthy. People tend to think about and focus on lifespan, using drugs and surgery to prop up health while enduring a process of slow breakdown and decay. But if you lengthen your healthspan, you’ll get more years of active, energized, and disease-free life. Isn’t that what we all really want?

When we look at the health profiles of the longest-lived humans (the supercentenarians who live past 110), we see clearly that they eventually develop the same chronic diseases most people get. The critical difference between these people and the general population is that those who live the longest become sick only in the last few years of their lives—and sometimes only in the last few months or weeks. They have a long healthspan.

By contrast, chronic disease decline is typically long and slow, causing decades of disability and pain before the end. That’s how most people go, so it may seem inevitable, but the truth is that in most cases, whether or not you will spend the last few decades of your life in decline is not predetermined. In fact, it is mostly self-determined. How you live now—how you build and maintain your energy capacity—will determine how you live later.

There is a long-standing belief that longevity is inherited, but ac- cording to the most recent research, only about 10 to 20 percent of the factors that influence your lifespan have a genetic basis.(3) Lifespan in the U.S. has increased by about 60 percent since 1900, due in part to the reduction in infectious disease–related deaths as a result of public health interventions like sewage and wastewater treatment, food safety, vaccines, antibiotics, and changing cultural views of personal hygiene.(4) But since 2014, when the average life expectancy in the U.S. was 78.9 years of age, lifespan has been trending downward again.(5) According to the CDC,(6) life expectancy in the U.S. in 2020 was 77.3 years of age (averaging men and women—women’s lifespan is always a bit higher). Life expectancy dropped by another 1.5 years in 2020 due to the COVID-19 pandemic, but that just sped up what was happening already. The U.S. is shockingly low on the list of developed countries when it comes to lifespan. (Japan is the highest.)

If you look at the actual causes of death over the last decade, you can see that modifiable behavioral risk factors (e.g., poor diet, physical inactivity, smoking, drinking, excess stress, social disconnection, etc.) underlie most of the chronic diseases that are killing us. Take the number one cause of death, heart disease, which kills more women and men than any other disease and costs about $1 billion every day in medical costs and productivity losses.(7) Heart disease often strikes in middle age—a surprising number of people have heart attacks between the ages of thirty-five and sixty-four—but according to the American Heart Association, 80 percent of cardiovascular disease, including heart disease and stroke, is preventable.(8) Cancer, another common cause of death, may also be at least 50 percent preventable(9) through strategies like quitting smoking, eating a more nutritious diet, drinking less alcohol, getting vaccinated against viruses like hepatitis and the human papillomavirus (HPV ), and taking measures to protect against skin cancer.

Then there is diabetes, which is startlingly common in the U.S. More than 10 percent of Americans have diabetes, one in three has prediabetes, and rates are rising fastest among young people.(10) But only 10 to 15 percent of Type 2 diabetes risk is genetic, which means that the development of this disease is highly influenced by lifestyle, socioeconomic, and environmental factors. Tragically, 84 percent of people who have prediabetes aren’t aware of it, and 21 percent of people with diabetes are undiagnosed.(11)

Most twenty-first-century humans have lifestyles and environments that create the conditions for mitochondrial dysfunction. This impairs metabolism, leads to insufficient energy capacity, sets off inflammatory alarm signals, ages us prematurely—and results in the development of chronic disease. Because mitochondria—organelles inside of our cells—produce energy, the number and health of our mitochondria determine our energy capacity. That is why I call the mitochondria our “batteries.” Compromise your battery capacity and you compromise your health, because your body has less energy to devote to keeping you well.

It is true that there will always be a percentage of the population who, for some reason, become sick despite what their genetics and lifestyle should predict. But it’s also true that most people can prevent or delay the onset of chronic metabolic disease by maximizing energy capacity and minimizing energy drain.

Since most people today are living with suboptimal energy production, it’s not surprising that, according to the National Center for Chronic Disease Prevention and Health Promotion, 60 percent of Americans already have at least one chronic disease.(12) I’m not trying to live to 150 like many Silicon Valley longevity seekers. What I care about is maintaining my quality of life for as long as I possibly can. At some point, our lives will end, but the end of a functional body and a functional brain does not have to precede the end of life—at least, not by as much as we tend to think.

If you start optimizing your energy capacity when you’re still healthy (or even just fairly healthy or somewhat healthy), you could significantly delay the onset of disease and disability. You can square off the healthspan curve, ensuring a better quality of life for longer. If you are lucky, you may end up as one of those supercentenarians who celebrate their 110th birthday in good health.

Increasing healthspan to the maximum possible requires that you stop doing things that compromise energy capacity and start doing things that increase energy capacity. It’s really that straightforward. If you want to build health, live longer, and lengthen your healthspan, the goal is to build your energy capacity by optimizing your mitochondrial function. Create more and bigger batteries with more capacity to store energy, keep them charged, and use them wisely. That’s how you get your spark back. And that, at its crux, is the foundation of health.

Health Is the Ability to Adapt

To truly understand how energy capacity underlies health, let’s take a closer look at what “health” really entails. In 1948, the World Health Organization (WHO) defined health as “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.”(13) That’s a high bar, and a pretty unrealistic one. Humans tend to catch viruses, break parts of themselves, and generally experience wear and tear with age, especially if they live life vigorously. Who would you say is healthier: the person who sits in a chair all day eating salad and taking no risks, or the person who climbs mountains, dives into oceans, and travels the world, and because of all that, has suffered from stress fractures, ruptured tendons, and the occasional rogue virus? Part of understanding what health is, is to think about what health is to you. How do you want to use your energy? What do you want to get out of your life? Do you value safety or adventure? A contemplative life or a dangerous one?

Taking this personalization into account, I think the best, most accurate description of health I’ve seen comes from Machteld Huber’s 2011 definition(14) of health as “the ability to adapt and self-manage in the face of social, physical, and emotional challenges.”That is how I define health—the ability to adapt to adversity. Life is constantly hitting us with challenges, and how we react and adapt to those challenges is the real marker of health. Our health is tested by our capacity to handle major stressors and be resourced emotionally, physically, spiritually, and socially to bounce back and continue to thrive.

Unfortunately, too many women are already in the process of mental and physical breakdown. They aren’t adapting. If you have a chronic disease, you aren’t adapting. If you’re tired all the time, you aren’t adapting. If you can’t stop overeating or undersleeping, overworking or underperforming, overstressing or underexercising, isolating or obsessing over social media, running on caffeine and fumes or self-medicating with alcohol or other substances, you aren’t adapting.

Why don’t we know how to adapt to adversity? That’s the four-trillion-dollar question (because that’s the amount of money people spent on healthcare in 2020(15)). People—especially women—are tired, worried, burned out, and stressed. We push ourselves to overachieve, agonize over the future, and feel paralyzed by a fear of failure (or a fear of success). Many of my female friends and followers describe dealing with the insidious effects of trauma, clinical depression, debilitating anxiety, and an inner battle about the basic worth of and ownership over their own bodies. Something is obviously wrong, but we see few mainstream solutions other than vague general advice like “Lose some weight” or “Get more sleep” or “Try not to be so stressed.” And these issues are affecting younger populations than ever before. According to the American Psychological Association,(16) millennials and Gen Z report the most stress of any age group. It used to be that the youngest adults had the brightest spark. That has been compromised by the human energy crisis.

But there is hope. Even if your doctor isn’t telling you what to do about your undiagnosable, vague, life-compromising symptoms of energy depletion, there is plenty you can do on your own. You can start slowly and gradually build your energy capacity back up again. You can make more batteries, keep them charged, and use them in a way that increases their capacity rather than draining it. This is how you create a more resilient body that can adapt and manage in the face of adversity. This is how you turn up your spark.

Assessing Your Spark

If you were a video game character, what would your energy level look like right now? Are your levels topped off, or are you on the last of your lives? Imagine you encounter an opponent, and you lose all your energy. If you have multiple lives, you might live to fight another day, with a fresh tank, as you keep playing and achieving greater energy levels with greater skills mastered. But if you don’t build up your energy levels, you’re not going to get to play the game for very long.

Understanding this concept is the key to unlocking the techniques in this book. If you think about your energy capacity, as measured by your mitochondrial health, in those terms, it can be easy to conceptualize what lowers your energy level and what fills you up. You have to build your health every day, like a muscle, to keep increasing your energy capacity, and you build it by way of the choices you make. The more capacity you build, the more dividends you reap and the better you can adapt to stressors.

Before I started taking my health seriously, I was drinking way too much caffeine, I didn’t sleep well, and I never exercised. I was lazy with my nutrition—I would eat cereal as a meal (multiple times a day). I had no stress management practice and I had tons of anxiety. I wasn’t building up my energy levels with sleep, exercise, and good food. I was draining my energy levels. After I started cutting back to a cup of coffee a day, sleeping regularly, doing yoga daily, eating a more plant-focused diet with balanced nutrition, and meditating regularly, I was able to do more work with less effort.

Understanding how to do that requires knowing where you are, then setting goals for where you want to be. You can start by frankly assessing your energy levels right now. Here are some signs that you have insufficient energy capacity:

  • Running out of energy before the day is over. Do you feel like you need a nap (or a double espresso) halfway through the day? If you can’t make it to bedtime without feeling like you’re dragging, that’s an obvious sign of drained batteries.
  • Groggy mornings. How do you feel when you wake up in the morning? A lot of people can’t get out of bed without an alarm. Waking up naturally and feeling good in the morning is a sign of high energy and good health.
  • Poor sleep. Do you sleep peacefully throughout the night or do you wake up frequently? Sleeping soundly through the night and feeling refreshed in the morning is a marker of energy capacity and an important way to charge your cellular batteries.
  • Generally unstable mood. If you often feel erratic, have mood swings, or feel anxiety or depression, these are consequences of poor health or health problems. Low energy capacity has negative effects on the brain. Your brain uses more energy than any other organ in the body, so when your energy system fails, so will your brain.
  • Inability to focus. If you are struggling with focusing on work and finding it hard to concentrate, this is another sign of energy deficiency. Brain fog and the inability to manage a complex life are signs that the brain isn’t getting a steady stream of energy.
  • Needing to eat all the time. This could be a sign of stress, blood sugar regulation problems, or a high-carb, low-nutrient diet contributing to metabolic inflexibility, or difficulty switching from burning carbs to burning fat. Over time, this leads to reduced energy capacity. Overeating is one of the quickest ways to compromise mitochondrial health.
  • Poor relationship quality. This one may not seem directly related to health, but if you don’t have at least several deep relationships with other people, it will be very difficult to be truly healthy. Healthy, supportive relationships greatly reduce stress and improve quality of life. Not having these can seriously compromise energy capacity.
  • Low stamina, endurance, and strength. If you have issues with stamina, endurance, and strength, those are direct reflections of a lack of sufficient energy. With a lot of energy capacity, you’ll have an easier time with exercise, even when you’re just getting started. If you struggle with a few flights of stairs, your mitochondria need attention.
  • Flexibility and bone strength. Weak bones and stiff joints are a sign of declining energy that is compromising your structure.
  • Dull senses. Your senses are related to nerve function. Good vision, hearing, sense of taste and smell, and sensitivity to touch are reflective of strong electrical “wiring.” Dull senses mean the wiring isn’t working.• dull skin. When you look at somebody who’s really vibrant and healthy, they look like they emit light (even as they age). This is called skin autofluorescence. Compare that to somebody who looks sallow or who has poor skin quality, whether that’s cystic acne, excessive wrinkles, or dullness. These are signs that there is some form of hormone dysfunction (often due to insulin resistance). People who suffer from diabetes and have impaired mitochondrial function have skin that emits less light than healthy people’s.(18)
  • Visceral fat. While many look to the number on the scale as a marker of health, what matters more is the type of fat you have. A little bit of excess weight isn’t going to harm you, but if you have visceral fat (the fat that gets packed around your organs)—even if you are slender— then that is a marker of poor health. This is best measured by a DEXA scan or MRI, but it’s also indicative of visceral fat if you are a woman and your waist size is greater than thirty-five inches (or greater than forty inches for a man).
  • Brittle hair or nails. These are external markers of health, like leaves on a tree or a plant. Droopy, dead, or shedding leaves (out of season) on a tree are signs that the tree isn’t healthy, and stress-related hair loss or dry, brittle, or prematurely gray hair(19) (defined as having gray hair before the age of twenty in Europeans, before twenty-five in Asians, and before thirty in Africans) can be a sign of mitochondrial dysfunction. If you checked multiple boxes on this list, you are probably suffering from insufficient energy capacity, and it’s most likely due to your
  • Lifestyle. There are four basic factors that reduce energy capacity and four basic factors that increase it. Think about how you are doing in each of these areas:
    Reduces energy capacity:
    – Inactivity
    – Overeating and poor nutrition causing chronic inflammation
    – Too much stress
    – Social disconnection
    Increases energy capacity:
    – Exercise and recovery, to build cellular batteries
    – Eating the right foods in the right amounts at the right times, to charge cellular batteries
    – Effective stress management with sufficient sleep, meditation, and nature exposure, to properly use cellular batteries
    – Human touch and connection, to plug in and thrive

Throughout this book, I’ll share biohacking strategies to help you overcome the challenges on the first list and embrace the habits on the second list, so you can maximize your energy production to increase your healthspan.

Preparing to Pursue Health

Energy is the foundation. Biohacking is the means. Health will be the result. It’s not complicated, but it requires a commitment to create health within yourself.

Pursuing health may sound like something everyone would want to do, but when it comes to making actual lifestyle changes, the reality can be more difficult than the concept. You know you should exercise and eat more vegetables, but what if you just don’t have the energy to do what it takes to create energy? Or what if you simply lack the material or emotional resources required to thrive?

You can only start where you are and work to the best of your ability to take steps in the right direction. But that’s all you need to do. You can invest a lot of time or a little. You can spend a lot of money or none. You can have big goals or small goals. It’s your path. Whatever you want to do or can do, this book can help you do it your way. Biohacking is ultimately personal. It’s about learning to listen to your own internal wisdom, whether you do that with fancy tech or just by getting quiet with yourself and paying attention.

The energetic changes I’ve experienced by biohacking my health have been incredible, inside and out. I have more energy, better focus, better digestion, and a sharper mind than I’ve ever had before (not to mention, my hair is thicker, my nails are stronger, and my skin is clearer—these are external markers of health). But to really inspire you to embark upon this journey with me, let’s look at some compelling reasons why making an effort (and I’m not going to pretend it’s not an effort) to pursue health is worthwhile. These are three bigger-picture advantages to actively pursuing health that you may not have thought much about before:

  • Survival/gaining evolutionary fitness. Simply put, if you’re healthy, you will be better able to run away if you need to, less likely to fall, and more able to lift heavy things (you never know when that might be a matter of life and death), fight off a threat, or think your way out of a bad situation. You’ll also have a more discerning immune system to fight off viruses, bacteria, and cancer cells that might try to take you down. Your heart, lungs, blood vessels, liver, kidneys, and pancreas will be stronger, so you’ll be less likely to get heart disease, lung disease, atherosclerosis, liver and kidney disease, and diabetes. You’ll have strong joints and dense bones, so you’ll be less likely to have a life-threatening accident, break a hip, or be crippled by arthritis. If you desire a family, your reproductive health is likely to be stronger. You’ll also be in a much better position to compete for the life you want in a world that still prioritizes the needs of men.
  • Having options, choices, freedom, and the capacity and inner resources to do meaningful work. Health gives you more possibilities and options. Energy helps you do more of what you want with your life, and that is what can give your life meaning. That could look like going to college, or building a company, or supporting others in your community. Whatever it is that is meaningful to you, energy capacity and the health it creates can be just what you need to commit yourself to your own life, your relationships, and your mission.
  • Having a better quality of life. Health means greater productivity, better efficiency, and less fatigue, so whatever you are doing, you can feel better and enjoy yourself more while you’re doing it. You’ll have increased focus and improved executive function, be in a better mood, sleep more peacefully at night, have inner calm and confidence in your abilities, live free of chronic pain, and maintain your autonomy as you age, since you will be less likely to be physically dependent on others.

Health is a means to an end that goes beyond just surviving. It’s the fuel for achieving your goals, actualizing your purpose, and achieving your potential. You can learn how to prepare your body for worst-case scenarios and monitor your body so that you can intervene before minor issues become serious problems. You can feel amazing rather than just okay. You can feel awake to your life rather than foggy and tired. And you can start right now.


Order The Spark Factor here.



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3. J. Graham Ruby, Kevin M. Wright, Kristin A. Rand, et al., “Estimates of the Heritability of Human Longevity Are Substantially Inflated Due to Assortative Mating,” Genetics 210, no. 3 (2018),

4. Michael Lustgarten, Microbial Burden: A Major Cause of Aging and Age-Related Disease (self-published ebook, 2016), -Major-Age-Related-Disease-ebook/dp/B01G48A88A.

5. “Deaths: Final Data for 2016,” National Vital Statistics Reports 67, no. 5 (2018): 76.

6. Elizabeth Arias, Betzaida Tejada-Vera, Farida Ahmad, and Kenneth D. Kochanek, “Provisional Life Expectancy Estimates for 2020,” NVSS Vital Statistics Rapid Release, report 15 ( July 2021),

7. “Heart Disease and Stroke Cost America Nearly $1 Billion a Day in Medical Costs, Lost Productivity,” CDC Foundation, April 29, 2015, https://www.cdc -day-medical-costs-lost-productivity.

8. “CDC Prevention Programs,” American Heart Association, May 18, 2018, https:// -programs.

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10. “National Diabetes Statistics Report,” Centers for Disease Control and Prevention, January 7, 2022, -report.html.

11. “Prediabetes—Your Chance to Prevent Type 2 Diabetes,” Centers for Disease Control and Prevention, December 21, 2021, /prediabetes.html; “National Diabetes Statistics Report: Estimates of Diabetes and Its Burden in the United States,” Centers for Disease Control and Prevention, January 18, 2022,

12. National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, .htm.

13. World Health Organization Constitution, /constitution.

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15. “CMS:USHealthCareSpendingWillReach$4Tin2020,”AdvisoryBoard,April3, 2020.

16. “Stress in America 2020: A National Mental Health Crisis,” American Psychological Association, October 2020, /2020/report-october.

17. Pauline Anderson, “Physicians Experience Highest Suicide Rate of Any Profession,” Medscape, May 7, 2018,; Centers for Disease Control and Prevention. “Supplementary Table 2: Male and Female Suicide Rates per 100,000 Civilian, Noninstitutionalized Working Persons Aged 16–64 Years for Major and Detailed Occupational Groups Meeting Reporting Criteria, National Violent Death Reporting System, Suicide Decedents (n = 15,779), 32 States, 2016,” Morbidity and Mortality Weekly Report 69, no. 3 (2020),

18. Esther G. Gerrits, Heeln L. Lutgers, Nanne Kleefstra, et al., “Skin Autofluorescence: A Tool to Identify Type 2 Diabetic Patients at Risk for Developing Microvascular Complications,” Diabetes Care 31, no. 3 (2008), /dc07-1755.

19. Deepika Pandhi and Deepshikha Khanna, “Premature Graying of Hair,” Indian Journal of Dermatology, Venereology, and Leprology 79, no. 5 (2013), https://doi .org/10.4103/0378-6323.116733.