I think most of us in our modern lifestyles have been convinced that fatigue and tiredness are normal parts of life. And we need shots of caffeine or energy bars to make it past a baseline tiredness. But when you look at other societies, particularly hunter-gatherer societies, you don’t even find words for being tired or being fatigued. We’ve been convinced that what happens to us is normal and that we need things to overcome this baseline normality.

There are some other striking myths. Most common are the adrenal fatigue or high cortisol myth. Patients often come to me with what they think is adrenal fatigue or high cortisol levels because they can’t lose weight or they can’t sleep. But 95 percent of these people, when evaluated, have absolutely normal cortisol levels and their adrenals are perfectly normal. And when we get to the underlying problem—their gut health—that’s when their symptoms are corrected. There’s far more going on than meets the eye. And one of the reasons I wanted to write The Energy Paradox was to look behind the curtain.

I like all my patients to realize that brain fog and “not having it in us” are mostly due to our immune system taking this energy and using it because it needs it. One of the most interesting studies is of one of the last remaining traditional hunter-gatherer tribes in Tanzania. Researchers looked at their energy expenditure and compared it to the energy expenditure of office workers. In the study, men walked eight to ten miles every day in search of game. And women walked from three to five miles gathering berries, plants, and tubers. They’re extremely fit and healthy. And when their energy expenditure was compared to that of office workers, shockingly both groups expended basically the same amount of energy.

How is this possible? It turns out that inflammation consumes a lot of energy. That was the cause of the additional energy expenditure in the office workers. I often see this in my patients—severe inflammation caused by leaky gut that contributes to their fatigue.

Other drivers of fatigue are the things we eat and the timing of our eating, which have totally changed over the last hundred years. We’ve gone from eating foods that are whole to eating foods that are broken down into very simple and rapidly absorbed sugars, proteins, and even fats. About 70 percent of our standard American diet is processed or ultraprocessed foods. Our mitochondria are not designed for this.

Mitochondria are good at processing glucose, proteins, and free fatty acids into energy. But they’re bad when all three things arrive simultaneously in huge amounts, which is what happens when we follow the advice of eating three square meals and two snacks a day. It jams our energy-producing highways.

That’s the paradox: The more we can control the timing of our eating period—by extending the length of time that we don’t eat and shortening the time that we do eat—the more energy we produce. But over twenty years of working with patients, I’ve found that it’s easier said than done. So we designed a six-week eating program that gradually reprograms your ability to shorten your eating window to seven hours and reset your metabolism.

Our microbiome is responsible for stimulating the production of much of our energy by interacting with our mitochondria through these exciting compounds called postbiotics.

Everybody’s heard of probiotics, the friendly bacteria. And in the book, I talk a lot about prebiotics, which are the food you have to feed the probiotics. But what’s been newly discovered is that probiotics make postbiotics, which are gases and short-chain fatty acids that turbocharge our mitochondria’s energy production. Postbiotics “talk” to the mitochondria to tell them either to make energy or to throttle back on energy production. The discovery of these won a Nobel Prize and shakes up everything we thought we knew about the gut.

One of the biggest energy disruptors is the widespread use of antibiotics. Broad-spectrum antibiotics might kill the bacteria that we think is infecting us, but it also kills all the bacteria that live in our microbiome. Another energy disruptor that I think deserves more scrutiny by all of us is the impact of glyphosate. Glyphosate is sprayed on corn, wheat, oats, and soybeans, and it’s in most of our wine. Glyphosate was patented as an antibiotic, and it changes our microbiome as any other antibiotic does. And recent animal research showed that that glyphosate produces leaky gut in rats.

Blue light is another energy disruptor that is everywhere. All of our devices, TV screens, almost all of our lighting in our offices and in our homes is blue light. Overexposure to the blue spectrum of light does two things: It turns on our hunger hormone ghrelin, and it suppresses normal sleep. So it’s a one-two punch—it makes us hungry and depletes our sleep. I own BLUblox and RaOptics glasses, which block both blue and green spectrums of light (green light may have effects similar to those of blue light).

Exercise “snacking.” Whether it’s walking or running or going to the gym or weight lifting or a HIIT class or jumping jacks while watching TV. You can break exercise down into manageable amounts—what I call exercise snacks. And there’s some cool research that shows that even a minute or two of walking up and down stairs gives you a huge benefit in producing more energy.