Don’t worry, you won’t be spreading this one to the entire office (unless you’re all in on some workplace group diet thing). The keto flu is your body’s natural reaction to carbohydrate restriction, which is a main component of the keto diet.
Going into ketosis, a metabolic state where your body burns fatty acids for energy instead of glucose, can be achieved by consuming a diet that is high in fat, moderate in protein, and very low in carbohydrates. As it turns out, we aren’t programmed to handle a complete cutoff of carbs and sugars without some unpleasant side effects.
Symptoms include: brain fog, headache, chills, sore throat, confusion, dizziness, insomnia, irritability, muscle soreness, nausea, trouble focusing, stomach pains, and intense sugar cravings. Three main changes that occur when you cut out carbs are mostly responsible for the flu: water and sodium flush out of your body in high volumes, leaving you with low insulin levels leading to dizziness, nausea, muscle cramping, headaches, and gastrointestinal issues; T3 and T4 thyroid hormone levels can drop, leaving you with a tired, foggy brain; and cortisol levels can spike in reaction to your body’s distress signals, heightening feelings of irritability and insomnia.
The keto flu usually kicks into gear about one or two days into the diet, and can last anywhere from a couple of days to two weeks, or even up to a month in severe cases. It all depends on your personal metabolic flexibility, or how easily your body can adapt to different fuel sources, which is determined by genetics and previous lifestyle habits. Been gorging on soda and fast food for the last few years? Yeah, this flu might be a rough one for you.
Thankfully, there are a few things you can do to combat the keto flu:
- Hydrate constantly to replace the water and sodium that’s gushing out of your kidneys.
- Sleep a lot, aiming for 7-9 hours a night to keep cortisol levels in check.
- Use an exogenous ketone supplement throughout the day for the first few days of the flu to up the ketone levels in your blood, which will help out with the fatigue and lack of energy.
- Eat more fats, especially MCTS, which bypass the lymphatic system so they can be used as fuel immediately, leading to quicker relief from flu symptoms.
- Sip on some bone broth to sneak in some extra water along with the sodium and potassium your cells are searching for.
- Don’t exercise intensely for a minute. Taking a walk or going through some yoga flows are great if they help you relax (and shrink those cortisol spikes), but don’t overdo the energy spend until your body has fully adjusted.
If all else fails, up your carb intake a tiny bit just to ease the transition. And don’t forget, on the other side of the keto flu is the fat-burning enhanced performance brought on by the keto diet, so try to stick it out.