You’ve decided to try the keto diet. The low-carb, high-fat diet can be great for performance and decreasing body weight, but the body needs a little bit of time to adapt to fat as an energy source. Often, there are some symptoms involved during this period of adaptation.

It’s called the “keto flu,” a commonly-experienced set of side-effects associated with carbohydrate withdrawal. This may sound like withdrawal from substance abuse; interestingly, recent studies have compared the effect of carbohydrates (particularly sugar) on the brain to that of addictive drugs like cocaine. Reported symptoms include: mood swings, irritability, fatigue, and dizziness. It can last anywhere from a day to a couple weeks.

Shortsighted dieters may allow keto flu knock them off the diet altogether–but after a period of metabolic adaptation, the body adjusts to the change and will reach a state where it’s burning fat as a fuel source, a largely-stored, but for many, a largely untapped bodily energy source. There are several ways to reduce, prevent or manage symptoms of the keto flu. We’ll discuss some of the most common symptoms, the science behind them, and offer some solutions to nascent keto dieters.

Restricting carbohydrates via dieting or fasting can cause an adjustment period for the body while it learns to use fat as fuel. Most of these symptoms are overcome through metabolic adaptation, but should they persist, see a dotor.

Top 10 Keto Flu Symptoms are: headaches, dizziness, cramps and sore muscles, fatigue, mood swings, irritability, and cravings, stomach pain and constipation, brain fog and difficulty focusing, bad breath and/or insomnia.

Science Behind Keto Flu

Carbohydrates are the body’s preferred energy source. When those are restricted, the body responds through a series of changes to transition from using glucose (stored carbs) for energy to using fat. This gear-switching is a good thing; but it’s also the reason for keto flu. First, blood sugar drops and causes hypoglycemia,, which is low blood sugar < 55 mg/dL. In response, the body changes both the fuel it uses for energy and how neurons in the brain function. Second, changes occur in other bodily systems that alter electrolyte, water and hormone levels–this can lead to dehydration from following the ketogenic diet.

Adapting to life without carbs

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Falling Blood Glucose

The physical consequences of sudden carb removal, we must first understand that our body generates energy using two main mechanisms: glycolysis (converting glucose to energy) and beta-oxidation (converting fat to energy).

Complying with a low-carb ketogenic diet means forcing the body to switch from using carbs as energy (via glycolysis) to using fats as energy (via beta-oxidation). After a period of adaptation, the body usually begins to generate energy from the breakdown of ketones (via a process call ketolysis) instead of glucose. This switch occurs because the body breaks down fatty acids into ketones so the brain can use them for fuel.

What happens when the body hasn’t yet learned to burn fat and produce ketones? That’s where hypoglycemia comes it. The result is a temporary energy deficit and low blood sugar. Remember: this is a transient period of adaptation. Switching to using fats and ketones as energy varies by person, depending on a mix of genetics and habitual diet; some individuals demonstrate a greater metabolic flexibility than others. These lucky individuals may show far fewer symptoms or experience the flu for a shorter duration.

Research has found the same pathways of the reward system in the brain are activated in both high-carb foods and cocaine or heroin. Both cause the release of dopamine (a “feel good” hormone). Regular carb consumption modifies gene expression and dopamine receptor availability in that reward system over time. This translates to a need for even more carbohydrates to have the same effect on those brain receptors. So the sudden removal of carbohydrates can lead to withdrawn symptoms, both physical and psychological.

Electrolyte Imbalance and Dehydration

Electrolytes are the minerals in the body that are derived from salts, e.g. calcium, potassium, magnesium, chloride, and sodium. Electrolyte levels, controlled by the kidneys, are crucial for maintaining bodily functions such as heartbeat regulation and muscle contraction.

Why does the ketogenic diet cause these imbalances? Carbohydrate restriction, and thus insulin release. With a lower carb intake, insulin levels drop.

Insulin signals cells in the body to absorb glucose in the bloodstream, and signals the kidneys to store more water. Lower insulin levels (as a result of decreased carb intake) means the kidneys now store less water. This results in dehydration and the flushing out of electrolytes in the process. Stored carbohydrates (glycogen) trap three grams of water per gram of glycogen–so this also causes a depletion while on keto, further contributing to the reduced amount of water and electrolytes in the body.

Hormonal Stress Response

A poorly-formulated ketogenic diet (one too low in calories or deficient in micronutrients) can trigger a starvation response in the body, thus raising levels of cortisol (stress hormone). Cortisol release is the body’s attempt to product the brain by raising blood sugar, trying to compensate for the now low blood sugar caused by carb reduction. If excess cortisol is released, stress response and blood sugar stability can become deregulated.

Thyroid hormones are also something to consider. They have several functions, including the maintenance and regulation of carbohydrate/energy metabolism. The T3 (or euthyroid) is the most biologically active form of the hormone, and is linked to dietary carb consumption. T3 levels have shown to decrease in response to carb restriction below a certain threshold (which varies from person to person). The result may be fatigue or difficulty focusing through the adaptation period. Conversely, lowered T3 is also hypothesized to bring several benefits if thyroid function is normal. This includes improving longevity and preserving muscle mass.

While discomfort may result during the transition, you can rest assured that lowered T3 does not appear to be indicative of hypothyroidism.

Solutions to Common Symptoms

Symptoms of the keto flu vary from person to person. But there are easy solutions one can leverage to help combat these symptoms.

If you’re looking for a supplement to help with keto flu, try HVMN Ketone, our flagship product. HVMN Ketone can give you an energy boost without the need for carbs, while keeping your blood ketone levels elevated. Try it here.

This article was originally published at HVMN.