Carb Withdrawal AKA Keto Flu

When starting a low carb or keto diet, many people experience a lack of energy. They may also experience headaches, muscle weakness, or feeling faint. This phenomenon is know as “keto flu”, although it might be more accurate to call it carb withdrawal. You may have heard things like this from people who are trying to talk you out of keto:

“I tried a low carb diet once, and I felt terrible. My body must just need carbs.”

No one’s body NEEDS carbs.

According to the US Food and Nutrition Board’s 2005 textbook “Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids :

“The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed.”

The problem isn’t that your body needs carbs, the problem is that your body needs electrolytes. When you follow a ketogenic lifestyle, your body retains much less water than it does when you eat a lot of carbohydrates. This means that when you start a ketogenic lifestyle you will release a lot of water from your system, and electrolytes will leave your system along with the water. This loss of water and electrolytes, along with a reduction in processed food intake (causing a reduction in sodium intake), are the main culprits in the symptoms of carbohydrate withdrawal. To prevent this, or to combat it if it has already started, you should be ingesting about 2 tsp of salt each day. I suggest measuring out 2 tsp (10 mL) of fine sea salt each morning and adding it to your food and/or water throughout the day, making sure it is all gone by bedtime. You should also be drinking plenty of water. A good rule of thumb is to drink half an ounce of water per day for every pound that you weigh. (32.6 mL per kg)

Another important electrolyte is magnesium. Nearly everyone is deficient in magnesium, because it is very difficult to get enough of it through food. I recommend 400-800mg of magnesium glycinate each day about an hour before bed. Start with 100-200 mg per day and increase your dose gradually over the course of a week or two. Another option is a topical magnesium oil or lotion. Avoid magnesium oxide and magnesium citrate supplements, because they are poorly absorbed and will have a laxative effect.

Potassium is another important electrolyte. However, animal proteins, especially beef, are high in potassium. Spinach and avocado are also high in potassium. For many people it is not necessary to supplement with potassium. Do not supplement potassium if you are taking prescription blood pressure medication.

If you follow my advice above to keep your electrolytes balanced, you can stop, or even prevent, the dreaded keto flu, so you can go from feeling terrible from running on carbs to feeling amazing from running on ketones!