Free Shipping on all US Orders over $100!

Four Natural Treatments to Beat the Keto Flu

Experiencing symptoms of the flu are uncomfortable and unwanted at any time, whether during times of seasonal flu and even more so now when panic can easily set in due to the widespread prevalence of the Coronavirus. However, if these symptoms appear within a couple of days of starting the keto diet, chances are you have the keto flu. Fortunately, keto flu symptoms like irritation, headache, lethargy and fatigue are short-term and usually subside after your body gets used to the keto diet. You can also rest assured that although keto flu symptoms are unpleasant, they are not contagious and cause no lasting harm. With a little care and planning, keto flu symptoms can be minimized or even prevented before their onset. But first things first, let's understand why you have the keto flu.

What Causes Keto Flu?

The reason for flu-like symptoms on the keto diet is because you are experiencing symptoms of carbohydrate withdrawal, a nutrient your body is used to having in large amounts. When you are on the standard American diet, carbohydrates typically provide 55% of your energy needs. But now that you have made a change to your dietary habits and embarked on the keto diet, your carbohydrate intake has decreased drastically so that only 5 to 10% of your energy needs are coming from carbohydrates.(1)  This means a change from 200 to 350 grams of carbohydrates to only 20 to 50 grams of carbohydrates per day.

Your body adapts to the change from a high carbohydrate diet to a very low carbohydrate diet by changing its source of energy in a series of actions. The first source of energy that the body turns to is carbohydrates stored in the form of glycogen, which is converted to glucose for energy. However, your body has limited stores of glycogen and once glycogen stores are depleted, your body turns to burning stored body fat as an alternate source of energy.(2) The conversion of fat to ketones (also called ketone bodies) is a process called ketogenesis. In the absence of glucose, the body makes ketones from stored fat to use as energy, and as this process continues, you begin to lose weight. (3) It, however, takes your body some time to adapt to using ketone bodies as an energy source and you may experience symptoms similar to flu during this transition time.

Keto Flu Symptoms

In response to low carbohydrate intake, your body decreases the production of insulin and starts converting body fat to ketones to replace glucose for use as energy. One side effect of low levels of insulin is increased urination. While this is good news on the scale as you notice a loss in weight, excretion of water, sodium, and potassium in urine is responsible for many of the flu-like symptoms when you start on the keto diet. The following is a list of common symptoms of keto flu, also referred to as keto-induction, reported in literature (1,4,5) by people transitioning on the keto diet:

  • Headache
  • Fatigue
  • Nausea
  • General weakness
  • Muscle cramps
  • Dizziness
  • Vomiting
  • Insomnia
  • Constipation
  • Diarrhea
  • Bad breath
  • Rash
  • Difficulty in exercise tolerance
  • Sugar cravings
  • Brain fog or difficulty in focusing

It is important to note that people respond differently to the change in diet, with some experiencing only a few, mild symptoms, while for others the symptoms may be severe. Additionally, there are some people who may never experience any symptom of the keto flu at all, transitioning effortlessly from their typical, normal diet to the keto diet. Similarly, time to shake off keto flu symptoms differs from person to person.

How Long Does Keto Flu Last?

Depending on the extent of change in diet and personal genetics, the onset of keto flu symptoms and duration varies. Some individuals may start feeling the symptoms of keto flu within a day or two of starting the keto diet, especially if the diet they are moving from is rich in simple sugars and processed foods. Others may notice the onset of keto flu symptoms within a week or so of starting the keto diet. But once your body gets used to the changed diet, keto flu symptoms may start to resolve in a few days. In some cases, the symptoms may persist for a few weeks before disappearing.(5) However, there are some simple steps you can take to beat the keto flu.

Best Treatments for Keto Flu

Increase Water and Electrolyte Intake

Loss of water, sodium and other minerals in urine may account for some of the keto flu symptoms you are experiencing. One simple way of reducing these effects is to make sure you are hydrated. Drink sufficient amount of fluids and ensure you are taking electrolytes like sodium, potassium and magnesium to make up for the losses occurring due to the increased urination. (1,5) You can start by including bone broth, chicken or beef stock, and soups made from nutrient-rich green, leafy vegetables in your diet to meet the increased need for fluids and electrolytes.

Change Source of Dietary Fat

If your intake of fat is mainly from coconut oil or palm kernel oil, both of which are high in medium chain triglycerides, you may experience keto flu symptoms such as diarrhea, abdominal cramps, and vomiting. A simple and easy solution is to add a variety of fat sources such as olive oil, avocados, and nuts to your diet. (5) These may help relieve some symptoms of keto flu, in addition to increasing satiety and providing variety to your diet.

Eat Healthy Carbs

If you have completely cut off your intake of carbohydrates since starting the keto diet, you may experience symptoms of keto flu. To avoid this unpleasant experience, taper off your carbohydrate intake gradually by adding some nutrient-dense, healthy carbs to your diet. Cutting out sugary, processed foods and replacing them with non-starchy vegetables such as broccoli or spinach, non-sweet fruits like berries, and different kinds of nuts will provide healthy carbohydrates to fight some of the symptoms of keto flu. (5)

Avoid Intense Workouts

While exercise is important to maintain or reduce body weight, you should avoid strenuous exercise early on the keto diet when you are experiencing symptoms of keto flu, especially muscle cramps, fatigue, and general weakness.  You should put intense workouts such as running, weight lifting and speed biking on hold until your body adapts to the keto diet and you are over any flu-like symptoms you may be experiencing. You may instead want to try gentle yoga, walking and stretching to keep moving without overdoing it. Increase exercise intensity slowly as you start feeling more energetic.


Although unwanted and uncomfortable, keto flu symptoms are a sign that your body is adapting to the high-fat, low-carb keto diet. Symptoms such as fatigue, headaches, and nausea are common when you first go on the keto diet and dissipate as your body adjusts to using ketones to meet energy needs. You can ease these symptoms by staying hydrated, replenishing electrolytes lost due to excessive urination, altering fat sources, including some amounts of healthy carbs, and going on low intensity exercise routines until your energy levels increase. 

About the author

Sukhsatej Batra has a Ph. D in Foods and Nutrition with a passion for motivating people to improve their well-being and achieve results through healthy lifestyle changes. Previously, Sukhsatej has worked as a Senior Research and Development Scientist and college professor.