Lifestyle choices have a direct impact upon our energy level at work. To avoid the low-energy doldrums at work, one important tactic is to control your insulin levels. This will allow your body to use fat more often than carbs for fuel, which will give you more energy. (Image courtesy of Pexels)

It’s mid-afternoon. You turn to a fellow co-worker (who’s hopefully not your boss) and say, “My brain is fried. I have no more energy to focus on my work.”

Technically, energy is a term of physics and thermodynamics. If we truly have “no energy,” then that would mean death (beyond starvation). But what we really mean is we’re feeling tired or lethargic.

In metabolic scientist Benjamin Bikman’s book, “Why We Get Sick,” he says the brain has enormous energy demands. Even at rest, it’s one of the most metabolically active tissues in our body (several times more than muscle). As such, it’s very sensitive to any energy deprivation. As our personal “fuel” runs low, our brain starts to sputter. Unfortunately, too many employees feel zapped of energy and “braindead” way too often. Here are 3 things you need to understand and do to re-energize your brain and body so you can continually perform at a high level at work.

1. Understand Your Body’s Fuel Choices

Whatever you’re doing at work — writing up a quarterly report, training your staff, or coming up with the next earth-shattering marketing campaign — your body requires energy to complete your tasks.

To understand how we access our body’s fuel for energy, you first need to know the three primary macronutrients: protein, carbohydrates, and fat. Protein is a building block. It’s what we’re made of. Protein gives our body the structure it needs to work and move.

It’s the other two, carbohydrates and fat, that are continually accessed by our body for fuel. Our bodies have the ability to switch back and forth between these macronutrients for fuel. This is called metabolic flexibility. 

Now, here’s what’s important: whether we use carbs or fat in our body as fuel depends on the hormone insulin. Put simply, insulin flows through our blood and determines which of the two energy sources the body will use.

If you want to avoid the low-energy doldrums at work, you need to control your insulin levels so your body uses fat more often than carbs for fuel. It’s as simple as that.

If we eat lots of carbs — from processed foods like bread, pasta, cereal, pizza, potatoes or donuts — our insulin levels can increase by 10x the normal level and remain elevated for up to 4 hours. This is bad.

When insulin is elevated, it gets most of its energy from carbohydrates. In other words, the body goes into a blood sugar-burning mode. Ultimately, if we’re burning more sugar then we’re burning less fat, which means the amount of fat on our body increases. (Yes, one of the keys to burning more fat is to keep your insulin levels low.)

If insulin is too high for too long, then it creates something called insulin resistance. 

“The reason I care about insulin resistance, and the reason I want you to care about it, is because insulin resistance worsens or can be the root cause for almost every chronic disease,” says Bikman.

Unfortunately, many of us eat so much refined carbs and sugar daily that insulin levels become stuck at a high level. That means the body remains in carb or blood sugar-burning mode. We’re preventing the body from switching to burning fat for fuel. This puts us in a state of metabolic inflexibility instead of the far healthier metabolic flexibility.

Here’s what’s interesting: We have enough energy in our stored carbohydrates for about 1 day of fuel, but we have about 100x more energy stored as fat. But as long as insulin levels are high, the energy stored in our fat cells is locked. Because our bodies have a constant need for fuel it will access this fuel from what’s readily available. 

How does this tie back into our energy level at work? After all the glucose in our bloodstream has been distributed and the energy from stored fat is not easily accessible because of the presence of insulin, we begin to feel sluggish (i.e., “low energy), hungry, and begin craving more food. It makes us feel like we’re running on empty.

By reducing carbohydrates and focusing more on proteins and healthy dietary fats, insulin levels will remain low. This allows you to unlock the energy stored in fat cells and start burning fat for fuel. 

The good dietary fats are saturated and monounsaturated fats. Saturated fats include fats from animals (meat and butter/ghee) and coconut oil. Monounsaturated fats comes mostly from fruit fats (olive and avocado) and certain nuts (like macadamia nut oil). Do all you can to avoid polyunsaturated fats like soybean, corn, canola and cottonseed oils, which are incredibly unhealthy and are found in high amounts in processed foods.

Besides keeping your insulin level low, there’s another benefit to burning a lot of fat for a prolonged period. The body will begin producing these small, little pieces of fat molecules called ketones. Multiple published studies indicate ketones are highly beneficial because they can help with the brain, heart, muscle, body fat and inflammation. Human studies show that when the brain is fed ketones, the brain starts to work better. Memory improves and clarity in thinking is enhanced. Ketones also help the heart work more efficiently by beating more blood every time it contracts.

Of course, a better-working brain, improved memory, greater clarity in thinking, improved energy and a more efficient heart can only help enhance your work performance. See why ketones should be your new best friend?

As you make healthier food choices, you’ll find your cravings for unhealthy foods greatly decrease. 

2. Avoid the “Food Coma”

Your co-workers invite you to join them at the local all-you-can-eat buffet. You go and boy do you get your money’s worth!

But then you pay the real price.

Overeating can make you feel tired. Suddenly you find yourself nodding off at your computer or fighting to stay awake in the afternoon staff meeting. 

Overeating is a major problem. Some people are less addicted to specific foods and more addicted to feeling full [1]. Unfortunately, when we eat to this point, we may get what some call a “food coma.” This is heavily influenced by changes in insulin levels. If we overindulge in an insulin-spiking meal, we may get an overload of tryptophan (an α-amino acid that is used in the biosynthesis of proteins) to the brain. Insulin directly increases the uptake of tryptophan into the brain [2], which can contribute to the famous “sleepy” signal people feel after overeating [3]. 

3. Get Sufficient Sleep 

Your boss calls you into her office to brief you on an important new department initiative that she asks you to lead.

And you yawn. Then you do your best to fight off additional yawns. That may not be the message you mean to send your boss, but you can’t help it.

Of course, insufficient sleep will leave you feeling deprived of energy at work. Almost 70% of American adults report having trouble sleeping. 

Good sleep is defined by these four characteristics:

1. Falling asleep within 30 minutes of laying down;

2. Only waking once per night;

3. Falling back asleep within 20 minutes, and finally;

4. Waking refreshed and alert.

The absence of these four qualities is the definition of bad sleep.

When we don’t sleep well, we set ourselves up for metabolic failure. This can lead to feeling stressed [4]. Another metabolic problem that arises from poor sleep is the temptation to snack on junk food.

An important aspect of good sleep is body temperature. If we’re too warm, we won’t sleep well. In fact, increased body temperature is one of the most common causes of insomnia [5]. 

One way to keep your body temperature at a comfortably low level is to keep your glucose at a comfortable level. Yes, it’s time to again bring up carbohydrates. Spiking glucose, either by glucose infusion or excessive carbohydrate consumption (see tip #1) will spike your body temperature [6, 7]. The worst time to consume high-carbohydrate foods are right before bedtime. This will produce blood glucose and body temperature spikes, which will result in more frequent waking and a restless night of sleep [8].

Final Thoughts

Adjusting our body’s energy source for fuel, avoiding the food coma and getting sufficient sleep will substantially enhance your work performance. Consequently, unhealthy food choices, unwise food portions and sleep deprivation will likely leave you feeling energy deprived. Controlling your carbohydrate intake and insulin level is one powerful, simple way to help your body use energy better and give you more energy for work… and life. 


1 Silva, A. S., Cardoso, H., Nogueira, C., Santos, J. and Vilaca, H. (1999) Treatment of morbid obesity with adjustable gastric band: preliminary report. Obesity surgery. 9, 194-197

2 Cangiano, C., Cardelli-Cangiano, P., Cascino, A., Patrizi, M. A., Barberini, F., Rossi Fanelli, F., Capocaccia, L. and Strom, R. (1983) On the stimulation by insulin of tryptophan transport across the blood-brain barrier. Biochem Int. 7, 617-627

3 George, C. F., Millar, T. W., Hanly, P. J. and Kryger, M. H. (1989) The effect of L-tryptophan on daytime sleep latency in normals: correlation with blood levels. Sleep. 12, 345-353

4 Vgontzas, A. N., Tsigos, C., Bixler, E. O., Stratakis, C. A., Zachman, K., Kales, A., Vela-Bueno, A. and Chrousos, G. P. (1998) Chronic insomnia and activity of the stress system: a preliminary study. J Psychosom Res. 45, 21-31

5 Cahill, G. F., Jr. (1971) The Banting Memorial Lecture 1971. Physiology of insulin in man. Diabetes. 20, 785-799

6 Broussard, J. L., Chapotot, F., Abraham, V., Day, A., Delebecque, F., Whitmore, H. R. and Tasali, E. (2015) Sleep restriction increases free fatty acids in healthy men. Diabetologia. 58, 791-798

7 Joo, E. Y., Yoon, C. W., Koo, D. L., Kim, D. and Hong, S. B. (2012) Adverse effects of 24 hours of sleep deprivation on cognition and stress hormones. J Clin Neurol. 8, 146-150

8 Schmid, S. M., Hallschmid, M., Jauch-Chara, K., Born, J. and Schultes, B. (2008) A single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal-weight healthy men. J Sleep Res. 17, 331-334