I embarked on this mission a week ago to display how efficient simply not eating is when it comes to losing weight. Most people are under the impression that you’ll die or be sick if you don’t eat food for a week. They think it’s dangerous or unhealthy.
As it turns out, it’s one of the healthiest things you can do for your body. The immense healing effects of being in a fasted state for a long period of time cannot be overstated. Oh and if you’ve got a bit of weight to lose, there’s no better way to do it.
Here’s my before and after pictures, the left is exactly 7 days prior to the right.
How Much Weight Can You Lose On A 7 Day Water Fast?
I weighed myself at 5am in the morning and 8pm at night every day for the week and below is a visual representation of how quickly I was able to lose weight.
I was able to lose a total of 7.43kg or 16.38lb in 7 days. My rate of weight loss was 1.06kg or 2.33lb per day.
If you also want to lose that much weight or more, you need to make sure you prepare properly.
How To Prepare For A 7 Day Water Fast?
This is so important and has a huge impact on just how big your results at the end of the fast will be. Now if you’re doing the fast for healing purposes, this is far less important. But from a weight loss perspective, this stuff is vital!
Go Keto For 2-4 Weeks Beforehand If Possible
I realise no one is probably planning week-long fasts several weeks in advance, but if you can, it’s a great idea. If you’re eating full keto for weeks before your fast, you’ll be in a fat adapted state. That means your body is extremely efficient at burning fat for fuel.
If you come into the fast having eaten carbs recently, your body is not going to be in ketosis and is going to have a more difficult experience transitioning to its fat burning mechanism. If you’re already fat adapted, you’re essentially hitting the ground running when you begin your fast and your overall weight loss will be much higher.
If you can’t spare a few weeks before the fast, at least try to do 2-3 days of keto beforehand so you’ll be in an entry stage of ketosis going into the fast which will be better than just going cold turkey on carbs.
Detox From Caffeine 2 Days Beforehand
If you won’t be consuming caffeine on your fast, this is good practice to make sure you don’t get any nasty withdrawal symptoms during your fast. Sometimes when I stop drinking coffee, I’ll get an awful headache about 24-36 hours after and if that happens on a fast, it’s not ideal since we don’t want to be taking pain killers if possible.
High Fat Final Meal
The reason we want a high fat meal going into our fast is to keep our stomach size as physically small as possible.
If you eat a huuuuge final meal, your stomach will expand and you’ll enter your fast with a distended stomach which will cause you to feel much hungrier. Fat will make you feel satiated from a lower overall food volume. So you can feel nice and full while keeping your stomach nice and tight.
My article How To Prepare For An Extended Water Fast discusses all of this in much greater depth.
Can You Work Out While On A 7 Day Water Fast?
Yes, but there is a right and wrong way to do it. I lifted weights 3 of the 7 days and did cardio 1-2 times everyday. Below I’m going to explain briefly why I continued working out and what things you need to keep in mind when doing so. This is what my schedule looked like, by the way.
Why You Should Work Out While On A Prolonged Fast
As an athlete, one of my major priorities when on an extended fast is to maintain as much muscle as possible. Gaining muscle is difficult and losing it is really easy. The primary reason we lose muscle is from being sedentary.
So in fact one of the worst things you can do during a long water fast is just sit around all day. Because your muscle will atrophy. You need a ‘training stimulus’ to stimulate the process of muscle protein synthesis.
Some people think it’s best to avoid working out entirely because they figure they’ll be burning pure muscle when they’re not getting any protein. But the reality is that resistance training is imperative for hanging onto the muscle mass you do have.
How To Work Out Properly On A Prolonged Fast
I wrote a full article on this titled Lifting Weights While Extended Fasting that goes into a lot more detail than I will in this article.
But the gist of it is you want to stay in your aerobic energy system at all times. That means keeping heart rate low, exertion to a minimum, you don’t want to be huffing and puffing, sweating is a bad sign, etc.
So for cardio this looks like walking. Walking is the ideal steady state cardio to do on an extended fast because it allows us to burn pure fat. Running and HIIT aren’t going to burn fat as efficiently and may end up burning some muscle.
Keep your workouts relatively short, use moderate to high weight, low reps, low sets. You just want to stimulate the muscle and let your brain know that it’s still being used. Use 80-90% of your normal weight, but shave off some sets and reps. Keep your heart rate low and avoid continuing sets when you’re noticing a big lactic acid buildup.
This is imperative if you’re going to be doing any physical activity on your extended fast. Because you’re urinating and sweating out all your electrolytes and not replenishing them, you’ll end up feeling extremely weak and lethargic.
Mix up 1 teaspoon of sodium chloride (table salt or pink Himalayan salt) with 1 teaspoon of potassium chloride (‘No Salt’ or ‘Lo Salt’) into a liter of water. Shake well and you’ve now got a perfect electrolyte concoction that’ll give you superpowers while on your extended fast.
Seriously, it’ll make you feel way better and give you tons of energy!
How To Break A 7 Day Water Fast
Look, there’s tons of different ways to go about doing this. Some people prefer eating fruit initially; some think eating fat only is better. I honestly don’t think it matters too much.
There are some key things to remember when breaking an extended water fast but by far the most important thing to remember is to be gentle!
Your digestive system has essentially been asleep for a week. Whatever you break your fast with, you need to keep the portion sizes to an absolute minimum. Gradually ease into it.
For a 7 day fast, I recommend taking a good 24 hours from the moment you break the fast til you’re eating normal meals again. If you weren’t drinking electrolytes, you need to be even more gentle.
What Not To Do
Just stay away from carbs and dairy. And don’t salt your food.
Keep carbs out of the equation for a good 24 hours if possible. The reason we’re avoiding carbs is because we’re hyper insulin sensitive and any carbohydrates are going to cause a massive insulin spike and cause us to switch into ‘fat storage mode’.
On top of that carbs will cause water retention which will make us look puffy and bloated.
Dairy is typically pretty difficult for our body to digest. We want easy to digest foods when breaking the fast. That said, yoghurt has been recommended by some quite reputable people as a decent choice for breaking the fast because of all the good bacteria you’ll be fueling your gut with.
Whatever your opinion on dairy/yoghurt, the main thing is to keep portion sizes small and to be gentle!
Avoid putting salt on your meals because when combined with insulin will cause some water retention. Plains foods are best here.
Consider Staying Keto
If you want to keep the fat burning train rolling after you’ve broken your fast, consider following a keto diet post-fast. I write all about the benefits of doing this in my article How To Break A Fast The Keto Way. This is ideal for people who want to avoid rebounding and have more weight to lose!
Here’s What I Chose To Break My Fast With
- Apple cider vinegar + baking soda – 2 Teaspoons of ACV and 1/2 teaspoon of baking soda. The purpose for this concoction is to help activate our digestive enzymes so our body is primed for breaking down solid food. It’s also a great way to give our kidneys a final wringing out.
- Lemon juice – 4 Tablespoons of lemon juice to help stabilise our blood pH balance and improve metabolism. This one’s definitely not necessary, but if you’ve got some lemon juice lying around, why not!
- Bone broth – Chicken broth was all I could find unfortunately. Still a nice and gentle way to break our fast without involving insulin.
- Sauerkraut – Fermented food is a brilliant first solid food to introduce as it’s going to populate our gut with good bacteria. Will have a few fork fulls of this.
- Spinach soup – I have no idea what the calories are in this because the label is in Thai, but decided I’d grab it anyway.
- Steamed vegetables – These are good for getting some goodness back into our gut. I don’t want to have too much however as we don’t need a ton of fiber right away.
- Chicken breast – Finally, 150-200g of plain lean chicken breast. This is a great solid protein to reintroduce.
I chose to snack on this stuff for a good 24 hours before going into more substantial meals. Again, you don’t have to pick these foods. There’s no right or wrong answer really, as long as you’re keeping carbs to an absolute minimum you’ll be fine.
Happy to field any questions in the comments below!