Struggling with nausea, headaches, muscle aches 6 days into 7 day fast

Hi y’all, as the title says I’ve been struggling with nausea, headaches, muscle aches 6 days into my 7 day fast. I’m 26(F), 5’0 and currently weigh 166 pounds (started this current fast at 173 pounds). For more context, here’s what I’ve been supplementing my water fast with: -3/4 teaspoon of lite-salt (870mg salt, 1050mg potassium) dissolved in 1 liter of water. I drink it slowly throughout the day and repeat 3 times a day. So that means everyday I have a total of 2610mg salt and 3150mg potassium. I’m also drinking 3 additional liters of plain water through the day. -1 magnesium pill in the morning and one in then evening. Each being 250mg for a total of 500mg a day. -1 L-tyrosine pill in the morning at 750mg. -I had plain ginger and turmeric tea days 2, 3, and 5 once each day but that’s it. I haven’t consumed any artificial sugars, coffee, broth, or chewed any gum. I should also note that I have been pretty sedentary for the most part. I went on a mile long walk on day 4 and did some light body weight stuff but nothing too heavy. So days 1-4 I felt fantastic. Lots of energy and focus, really productive at work. I had the occasional hunger pang but nothing I couldn’t handle. By day 4 my hunger pangs started to go away, and by day 5 they were completely gone. However, on day 5 I started to get headaches and muscle aches. This morning, on day 6, I took 3 teaspoons of salt with water to help with the aches and that only made me feel incredibly nauseous and it hasn’t gone away since. It’s been a few hours now. What should I do? Have I not been supplementing enough? I really want to make it to 7 days so any help with be appreciated. I’ll power through regardless but I don’t want this to happen again during extended future fasts. Random note: I have plans to go to the movies tonight where I will be tempted with the powerful aroma of buttery popcorn throughout the theater. Since I don’t have much of an appetite rn I think I’ll be good but still wish me luck😭

Answer

If you’ve never fasted before it could be something called “keto flu.” As your body enters the deeper stages of ketosis - where it’s truly just running off stored fat reserves instead of carb induced glycogen, there’s sometimes flu-like symptoms that take hold. Also known as keto flu.

People who try to start a ketogenic diet for the first time usually run into this as well since their dietary goal is to maintain a higher level of ketones in the blood by eating almost no carbs.

Kinda bro science here but nobody’s really sure what causes this. Body detoxing or just not knowing how to handle itself? Withdrawal if your diet before consisted of a lot of bad carbs? Also fat doesn’t really burn as efficiently as carbohydrates so maybe the body isn’t sure how to run on it. Carbs are awesome if you’re fueling up for a heavy workout. But if you’re only running on fat, you may not be able to work out at all for a few days or you kinda have to take it easy. It’s like putting watered down gas into a car.

The good news is it goes away. Take it easy, drink lots of water. It sounds like you’re getting your electrolytes.

Further reading: https://www.health.harvard.edu/blog/what-is-keto-flu-2018101815052

Also you may want to buy a ketones monitor. I’ve got the one from Keto Mojo and it’s kind of a fun science experiment to watch my ketone levels through all of this and how they react to various things like working out, etc.

I’m on Day 3 of a fast and now you have me thinking about buttery popcorn lol.

Edit: I’ll add that I’ve fasted before - as much as 12 days. But I’m having a MUCH easier time of it this time since I ate fairly ketogenetic for about a week leading up to starting the fast. I was working out hard in the mornings and eating basically zero carb except for immediately before and after my workouts. So I was in moderate ketosis a few days before I actually just stopped eating altogether. All the sudden one day I just wasn’t hungry. It helped having the ketones monitor so I could see where I was throughout the process.