Are you worried about starting the ketogenic diet because of the ‘Keto Flu’? Do you know what to expect?

In this article, we will discuss the symptoms of ‘Keto Flu’ and how to spot the difference between these symptoms and those from other illnesses such as influenza virus or food poisoning.

Read on as we learn about:

Transitioning into ‘Ketosis’

What to Expect

The state of ‘ketosis’ is not typically symptomatic 1. Most symptoms that arise are a result of carbohydrate restriction and lowering insulin levels in the body 2. This leads to the excretion of sodium by the kidneys 3, which is known as the ‘natriuresis of fasting’4. Insulin is a fat storing hormone. The levels drop as the body moves from using glucose over to fat and ketones, as a primary source of energy. During this transition, symptoms such as a headache, dizziness, and digestive disturbances may occur5. So when will you experience these symptoms?

How Long Do Symptoms Last?

Symptoms are most likely experienced between Day 1 to Day 4 of implementing a ketogenic diet. This is a diet of 20g of total carbohydrates or less. Taking steps ahead of time, to prevent the onset of these negative symptoms is important for a smooth transition into ‘ketosis’. It will also improve the likelihood of staying on the diet long term.

If you are prepared, these short-term symptoms can be avoided completely. This will make the journey into ‘fat loss ketosis’ more manageable
6. Let’s have a brief look at Keto Flu symptoms and how they differ to symptoms of other illnesses.

Dealing with Keto Flu Symptoms

‘Keto Flu’ more favourably known as ‘Keto Induction’. It presents as a combination of symptoms similar to those of the viral flu. For the most part, they are a result of a poorly implemented ketogenic diet. How to prevent Keto Flu symptoms can be quite specific and differs from person to person but there are some steps you can take to alleviate symptoms. These steps have three main areas of focus:

  • Electrolytes: If you are experiencing symptoms such as lightheadedness, headache, heart palpitations or fatigue you may need to balance or increase the amount of sodium, potassium and magnesium in your body
  • Fat Levels: If you are experiencing hunger cravings, irritability, nausea, diarrhoea or fatigue you may need to increase or decrease the levels of fat that you are consuming. There are also supplements available that can help to alleviate these symptoms.
  • Rest: Depending on a few external factors, some people may need to rest more than others in the first few days of the ketogenic diet, as the body moves into a state of ‘ketosis’.

Less Common Symptoms

There are other, less common symptoms of Keto Flu. Constipation (from reduced food volume and fibre intake), halitosis (bad breath), muscle cramps, and rash7 may also occur. These symptoms can be resolved with one or a combination of the three areas of focus stated above, electrolytes, adjusted fat levels and rest. So how do you know if you have the Keto Flu or a stomach bug?

Keto Flu Symptoms

Non Keto Flu Symptoms

Once a ‘well formulated ketogenic diet’ is followed, symptoms of the Keto Flu should not occur. A ‘well formulated ketogenic diet’ includes a wide range of nutrient dense proteins, fats and fibres.

It is important to vary your foods to cover all nutrients so that any symptoms that arise can quickly be identified as symptoms of another illness. If you are experiencing negative symptoms, the first step is to contact and consult with your doctor or pharmacist.

Now, let’s have a look at the most common questions on symptoms not associated with the Keto Flu and how to deal with them.

Does Keto Flu cause Nausea and Vomiting?

For the majority of people, Keto Flu does not cause nausea or vomiting. If symptoms develop quickly and are moderate to severe in nature, contact your doctor. If you experience prolonged diarrhoea or signs of fever, contact your doctor immediately to rule out other causes.

For a small number of people, the increased amount of fat in the diet can cause short-term fat intolerance8. This may result in low levels of nausea, vomiting and digestive disturbances such as diarrhoea. Once the fat levels are adjusted, symptoms should resolve almost immediately.

Does Keto Flu cause Diarrhoea?

Keto Flu does not cause diarrhoea for people following a ‘well-formulated ketogenic diet’. By using the tools, mentioned above it is possible to prevent the onset of symptoms. If you are experiencing diarrhoea, make sure to consume a wide range of nutrient-dense foods. It is important to keep your electrolytes in balance and stay hydrated.

For those starting the ketogenic diet, it is important to introduce fat slowly into the diet in order to test your fat tolerance levels. This will help to avoid any possible digestive issues.

Does Keto Flu cause Fever and Chills?

Keto Flu does not cause fever or chills. A fever is characteristic of a viral infection such as ‘Influenza’. It may also be characteristic of a bacterial infection which is not associated with the implementation of a ketogenic diet. It is important to consult your doctor if you are experiencing fever and chills.

Does Keto Flu cause Coughs, Sneezes and Running Noses?

Keto Flu does not cause coughs, sneezes or running noses. These symptoms are characteristic of viral infections such as ‘Influenza’ or the common cold. They are not associated with the transition into ‘ketosis’.

Does Keto Flu cause Joint Pain?

Keto Flu does not cause Joint Pain. Joint Pain may occur for many reasons, most notably from injury, inflammation, autoimmune conditions. It can also occur as a result of vitamin or mineral/electrolyte deficiency. Following a ‘well formulated ketogenic diet’ may decrease pain 9, inflammation10 and improve autoimmune conditions11. Ketogenic diets are anti-inflammatory by nature and therefore may improve and resolve pain in the joints.

Does Keto Flu cause Body Aches?

For the majority of people, Keto Flu does not cause significant body aches and pains. There is a research study that showed a small percentage of participants on a ketogenic diet experienced back pain12. However, this was not during the transition into ‘ketosis’.

Withdrawal Symptoms

Some symptoms of withdrawal can be experienced when transitioning into ‘ketosis’ between Day 1 and Day 4. The removal of refined sugars, carbohydrates and even caffeine can trigger the onset of negative symptoms. Nausea, vomiting, joint pain, diarrhoea and fever13 are often experienced. These symptoms are not characteristic of Keto Flu. They will resolve over time once the body has moved into a state of ‘ketosis’. Once in ‘ketosis’, the body will be using an alternate pathway to provide energy as fuel and symptoms should disappear.

The Difference Between Keto Flu and Flu Virus

Keto Flu vs Flu Virus

The Keto Flu does not arise as a result of a viral infection. It occurs through the transition from glucose usage to fat and ketone usage for energy. Under the term Keto Flu there are a series of negative symptoms. Some of these symptoms such as headaches and dizziness are also characteristic of a viral infection like the Flu Virus.

Though some of these symptoms are similar in nature, they are not part of the same ‘Flu’. The symptoms experienced during the transition into ‘ketosis’ are not contagious. They can be treated or altogether avoided with the correct approach.

If you are experiencing any form of negative symptoms as you start your ketogenic lifestyle it is always best to troubleshoot. Most symptoms can be improved with the right tools and techniques.

If you are experiencing symptoms characteristic of the flu on your ketogenic diet, contact your doctor or pharmacist.

Summary: The Takeaways

  • Keto Flu and Flu Virus share certain characteristics but they are completely unrelated. Keto flu is not an illness.
  • Most Keto Flu symptoms are results of a poorly implemented ketogenic diet which can be improved and even avoided with the right dietary correction.
  • If you are following a well-formulated diet and experiencing symptoms stated above of moderate to severe intensity, contact your physician/doctor immediately.
QUESTION(S): What questions do you have about Keto Flu symptoms that haven’t been answered in this article? Let me know by adding to the in the comments.

Study References:

  1. Palgi, A., Read, J. L., Greenberg, I., Hoefer, M. A., Bistrian, B. R., & Blackburn, G. L. (1985). Multidisciplinary treatment of obesity with a protein-sparing modified fast: results in 668 outpatients. American Journal of Public Health, 75(10), 1190–1194.
  2. Hamwi, G. J., Mitchell, M. C., Wieland, R. G., Kruger, F. A., & Schachner, S. S. (1967).Sodium and potassium metabolism during starvation. American Journal of Clinical Nutrition, 20(8), 897–902.
  3. Volek JS, Phinney SD. (2011). The Art and Science of Low Carbohydrate Living. Beyond Obesity Publishing, Miami FL. PP 41.
  4. Sigler, M. H. (1975).The mechanism of the natriuresis of fasting. The Journal of Clinical Investigation, 55(2), 377–87.
  5. Harvey, C. J. D. C., Schofield, G. M., & Williden, M. (2018). The use of nutritional supplements to induce ketosis and reduce symptoms associated with keto-induction: a narrative review. PeerJ, 6, e4488.
  6. Hartman, A. L., & Vining, E. P. G. (2007).Clinical Aspects of the Ketogenic Diet. Epilepsia, 48(1), 31–42.
  7. Yancy, W. S. (2004). A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia. Annals of Internal Medicine, 140(10), 769.
  8. Duchowny, M. S. (2005). Food for thought: the ketogenic diet and adverse effects in children. Epilepsy Currents, 5(4), 152–4.
  9. Masino, S. A., & Ruskin, D. N. (2013). Ketogenic diets and pain. Journal of Child Neurology, 28(8), 993–1001.
  10. Pinto, A., Bonucci, A., Maggi, E., Corsi, M., & Businaro, R. (2018). Anti-Oxidant and Anti-Inflammatory Activity of Ketogenic Diet: New Perspectives for Neuroprotection in Alzheimer’s Disease. Antioxidants (Basel, Switzerland), 7(5).
  11. Storoni, M., Plant, G. T., Storoni, M., & Plant, G. T. (2015). The Therapeutic Potential of the Ketogenic Diet in Treating Progressive Multiple Sclerosis. Multiple Sclerosis International, 1–9.
  12. Westman, E. C., Yancy, W. S., Mavropoulos, J. C., Marquart, M., & McDuffie, J. R. (2008). The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutrition & Metabolism, 5(1), 36.
  13. Juliano, L. M., & Griffiths, R. R. (2004). A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology, 176(1), 1–29.