Many people (not everyone!) who start a low carb diet experience what’s called the “keto flu” or the “induction flu” in the first few days while the body is adapting to burning ketones instead of glucose. The basic symptoms are:
- upset stomach
- Lack of mental clarity (brain fog)
It’s called the “keto flu” for a reason: you feel sick. I’ve gone through it and it wasn’t a pleasant experience. Fortunately it only lasted 4 days (2 of them were pretty bad) but then suddenly I woke up feeling much better, less hungry and my energy level was really high and consistent throughout the day! While at one point (or three or four) I thought to myself: “what the serious F am I doing? I’m going to die!” but I plowed through it and when it was over I didn’t regret a thing because what I gained mentally and physically was 100% worth it.
I have an autoimmune disease called Ankylosing Spondylitis, and Fibromyalgia to top it off. So, I’m no stranger to brain fog and fatigue, but the fatigue and brain fog that come with keto flu are a little different, and feel much more like having a regular flu.
How long will the keto flu last?
It depends. Some people don’t experience any symptoms at all, but some suffer anywhere from a day to a week. Rare cases up to two weeks. Everybody’s bodies are different and some people handle switching over better than others. You might consider starting keto on a weekend or sometime when you’re able to get good rest deal with the symptoms.
For those of you that are going through the keto flu, don’t give up! I know you feel like it’s never going to get better but stick with it and you´ll be so happy you did! I’m telling you, waking up refreshed for the first time in years, not getting the afternoon “blah” feeling and stuffing my face with carbs to try to boost my energy is the best side effect of the lchf/keto diet I’ve experienced. Okay, losing weight while eating good food, feeling full and satisfied is great too 😉
So what can be done to lessen the symptoms?
First you have to understand why your body is reacting this way. Your body’s been burning glucose for energy so it’s basically full of enzymes that are waiting to deal with the carbs you eat (and probably store them as fat) reference. But now the body needs to make new enzymes that burn fat for fuel instead of carbs, and the transition period causes your flu-like symptoms. There are some things you can do to lessen the symptoms of the keto flu and to make it go away sooner (to force the body to transition sooner) Ok, let’s get to the good part – what to do:
- First of all – you’re probably dehydrated. Drink PLENTY of water while you’re on the keto diet. And then some more.
- Watch your electrolytes. When the body is getting rid of excess insulin from your former carb-crazy diet you´ll lose lots of fluids that have been retained in your body. This causes the rapid weight loss most people see in their first few days of ketosis, it’s mostly water, sorry. When you lose all the retained water you also lose electrolytes like sodium, magnesium and potassium. When you’re lacking them you´ll feel like crap so when you’re feeling really ill on the keto flu try things like chicken/beef broth and look for foods rich in these minerals. Take a multi-vitamin and a multi-mineral. I have a hard time getting my electrolytes balance correct but I try because it’s really important when you eat low carb. 5 grams of salt, 1 of potassium and 0.3 of magnesium a day or you´ll feel bad. I don’t really like taking pills so I supplement with electrolyte tablets in my water. I usually go for the High5 brand and add lite salt that has extra potassium in it. I know that drinking salt water doesn’t sound great but honestly I don’t notice it because of the electrolyte tabs. If you get leg cramps try drinking bouillon for extra salt and have a relaxing magnesium drink before bed.
- Eat more fat – Yup, load up. Butter everything, bacon everything, eat fatty meats and put heavy cream in your coffee. This will force your body to hurry up the transition. You´ll think this is crazy and think you´ll never get skinny eating this way, but you will.
- Don’t eat too much protein – The body can transform protein into glucose so if you eat too much of it in the first days it will slow down the transition. Go for fatty meat and cheese if you can, add fat to protein shakes etc. The first instinct when you’re on a diet might be to nibble on a chicken breast to lose weight. Don’t do that unless it’s smothered in cheese, wrapped with bacon and has some mayo on the side 🙂
tl;dr: Drink water, replenish electrolytes (sodium, magnesium, potassium) with food and supplements, drink broth, eat fat and not too much protein.
If you’re wondering if you’re in ketosis already, check out my article: Am I in ketosis?
If you’re having trouble with bad breat on the keto diet, check out my article on keto and bad breath.
I really hope this helps. I know it helped me getting over the worst of the dreaded keto flu.