The ketogenic (keto) diet is a popular low-carb diet with a myriad of health benefits. Its premise rests on the theory that without sufficient carbohydrates (essentially sugars) the body will go into ketosis, or draw its energy from fat stores in the form of ketones. This diet can be a very effective weight loss tool if done correctly. However, anyone who has been on the keto diet for more than a week has likely experienced, or at least heard of, the keto flu. With symptoms that include headaches, fatigue, confusion, irritability, nausea, muscle cramps, and constipation it sounds almost like an awful, extended hangover where you don’t even get to enjoy a few drinks first. This is for good reason. The keto flu is not actually a flu in the viral sense, but instead refers to the common symptoms experienced at the onset of the keto diet. Some experience these symptoms for weeks or even months before adjusting fully, while others only for a few days. Don’t worry! With a deeper understanding of the keto flu and why a ketogenic diet can produce these symptoms it can easily be prevented and avoided.
What is the keto flu?
First, let’s be clear: no, this is not the flu; no, Nyquil won’t help you.
In reality, the symptoms of the keto flu stem from a combination of an electrolyte imbalance, low blood pressure, and your body’s natural adjustment period to a new diet. You have probably already heard of electrolytes, and know they need to be replenished during exercise. Electrolytes are used by the body to regulate the electrical impulses and reactions necessary for nearly all bodily functions. They are responsible for muscle contractions, waste production, and even brain function. It’s no wonder that any drop in your electrolyte intake will significantly impact how you feel. As part of the keto diet most people begin to significantly cut down on the amount of processed food they are eating, simply because it is easier to control portions and the type of food you eat if it is self-prepared. The unintended side effect of this is often a decrease in both general volume of food being consumed, as well as reduced amounts of salt, potassium, and magnesium. You may also notice that, once starting the keto diet, you will have an increased urge to urinate. This is a normal bodily response to entering ketosis. However, the increased urination causes the body to flush more of these essential electrolytes than usual. Thus, to avoid and treat the keto flu, you must work to replenish these essential components of a healthy diet.
How can I prevent the keto flu?
The keto flu can be easily prevented by remembering to ease yourself into your new ketogenic diet and by maintaining a healthy balance with sufficient water and essential nutrients. It is especially important for those people brand new to the keto diet to take things slow and easy. Ease into the new diet to give your body time to adjust. A ketogenic diet can be great, and very beneficial to many people but it is not, in fact, magic. Your digestive system is likely used to, and has adapted to, a diet largely consisting of carbohydrates and simple sugars. It’s also likely not used to the increased fat content and may be ill equipped to properly digest it at first. Without going into detail of the gut microbiota, your digestive system allocates resources according to what you normally consume. When you switch to a ketogenic diet the energy sources you are now consuming are different and your body needs to start reallocating those resources. Many of the gastrointestinal side effects of the keto flu, like nausea, stomach pain, and diarrhea, are related to this change. Therefore, the best way to prevent the keto flu is to take it slow. Do not jump right in and drop your carbohydrate intake all the way down to 20 g per day or your body will very quickly let its shock be known, causing you significant discomfort.
As always, you should listen to your body and always be sure you are drinking a sufficient amount of water as well as adding enough salt to your food. To some, this sounds counter intuitive; we are always being told to cut back on sodium for our health. This is something you will have to worry about less on the ketogenic diet. If you find you aren’t getting enough salt in your diet normally, many recommend supplementing your meals with salt-filled broth. Either bone broth made at home or simply a bouillon cube in a cup of hot water should suffice.
It’s too late, I already have the keto flu. How do I make it stop?
The best methods for treating the keto flu are the same as those for preventing it. First, increase your water intake. You don’t need to start toting around one of those gallon water jugs (or do if you find it helps) just be mindful of how much water you are really consuming every day. Chances are you probably weren’t drinking enough before you started the keto diet and you are almost definitely not consuming enough now if you are experiencing the keto flu. Many swear by concentrated salt water shooters or adding a few tablespoons of salt to your water that you are drinking throughout the day. Again, this can be made much more palatable by adding salt to your food or by drinking it in the form of a broth. Many report significant relief from headaches and fatigue by simply drinking a glass of water with a single teaspoon of salt. If you find that symptoms still persist it may help to begin taking both potassium and magnesium supplements until you can work them into your normal diet in sufficient amounts. Again, the keto diet is not magic and it is important to continue to have balance in what you eat. Dried seaweed snacks are a great way to boost both your magnesium and salt intake with the added benefit of giving you a snack alternative to potato chips!
The only way to truly be done with the keto flu is to give your body sufficient time to adjust to your new diet and to learn to function using the new energy source. Remember, although the human body is designed to go through starvation cycles, which is why the keto diet works, your body is likely not used to it. It is accustomed to being fed lots of bread and sugar, energy sources that are easy to break down and don’t require a lot of effort. Just like if you were to start a new exercise regime, your digestive system needs time to adjust to its new routine.