Here is the experience of someone who has been doing 10 day fasts every year for the past decade.

This is my personal anecdotal experience of what works and what doesn’t. I am a 6’1” male, and my ideal weight is around 195 lbs, but Ive used anything in the 190-200 range as my target weight.

I usually start fasting around the time I hit 215 lbs, which happens at about one year intervals. My longest fast was 14 days and my shortest 7 days. I have done about 10 fasts, and I have interrupted only one due to feeling unwell for a reason I couldn’t determine. My other 9 fasts went without major problems. The point is that you shouldn’t feel discouraged if you tried fasting once and had a bad experience, even experienced fasters can have those occasionally.

Benefits

I fast for only one reason, to lose weight so I don’t have to buy new clothes. I don’t fast for any spiritual or metaphysical reasons, although it’s absolutely true that during a fast my mental focus is razor sharp. I can pull off 8 hours of uninterrupted work at my desk and still feel okay, while I can do no more than 4 hours when I am eating. Yes, that means I am really unproductive during the other 4 hours, don’t tell my manager. Fasting for me is better than Adderal for mental focus.

Hunger

I feel the hungriest during the first 48 hours, after that the hunger goes in the background where it doesn’t really bother me but it never truly disappears. Smelling or seeing food, even pictures of food can bring instant cravings. Distracting myself by playing chess or video games or typing long posts on Reddit works really well in those situations. Here is the other point I am trying to make, don’t feel you aren’t doing it right or that there is something wrong with you if you still feel slightly hungry and don’t be discouraged by people who say their hunger disappeared completely, they are probably exaggerating.

Exercise

I don’t do my usual weight lifting during a fast. I am afraid of losing muscle mass, because I don’t believe you can gain muscle without protein, but that could be just bro science. That said, I do have the energy for extreme physical exertion, and I tested it once for science. I went on a 3-day backpacking trip, 8 hours of hard walking per day, sleeping in below freezing temperatures. I didn’t break down, nor did I get unusually tired, I felt surpassingly well. Feeling cold at night was the worst part. I took copious amount of electrolytes, because I was losing so much through sweat, I was licking the sweat running down my face because it tasted so good.

Electrolytes

I mix one tea spoon of baking soda and one tea spoon of lite salt (half sodium, half potassium) in about 4 cups of water. I add a good spritz of lemon juice, around a table spoon. This reacts with the baking soda and makes it bubbly and awesome. It tastes much better than the snake juice recommended here. I drink one of these cocktails in the morning and one in the evening. Some times I drink a third one if I feel nauseous or tired or have a headache (extremely rarely). Don’t stress about the table spoon of lemon juice breaking your fast, it’s nonsense.

I’ve tried adding magnesium to the mix, but it gave my diarrhea when I took a full capsule of magnesium glycenate. Magnesium is a potent laxative. I tried breaking the capsule and taking only half, but the powder is hardly water soluble so it’s practically impossible to mix it in cold water. So instead I just poor half a capsule directly into my mouth and wash it down with lots of water. It tastes bad, which is why they keep in the capsule probably. It’s an annoying process so I only do it once every two days.

Occasionally, I drink some pickle juice if I have any. No more than a few gulps, but still enough so it feels like a treat.

Drinks

I drink two mugs of brewed coffee in the morning. Brewed tastes better than instant coffee, but the latter is okay too. In the evening, especially if I am cold, I drink hot water with trace amounts of cocoa: one tea spoon of cocoa in 4 cups of hot water. I’ve tried normal amounts of cocoa, but it sends me straight to the toilet.

I drink a good amount of plain water during the day but I don’t go overboard. I prefer sparkling water to plain water. Flavored sparkling water (La Croix) makes me slightly nauseous, and I don’t like it anyways.

I absolutely stay away from the random 0-calories artificially sweetened drinks. I don’t remember the name of the drink, but during one of my first fasts, I drank one of those 0-calorie drinks you can buy from a vending machine and it made me extremely nauseous. Never again. I’ve tried Coke Zero, Diet Coke, Diet Pepsi. No side effects but I didn’t really like the taste so I stay away.

Tea. I occasionally drink tea, but it doesn’t taste as good as when I am not fasting, it actually tastes kind of weird.

No hard alcohol. On a few occasions I’ve drank a small cup of wine or beer, just because I was in a social situation and didn’t want to be weird. No, the world didn’t stop turning, my weight loss didn’t disappear.

Bad breath

Waking up is the worst part of the day because of the ketosis breath. Just tasting my mouth makes me nauseous. Brushing my teeth doesn’t make it much better, because the toothpaste tastes really weird and unpleasant while on a fast. A big reason why I go for the black coffee as soon as I wake up.

During the day I chew bubble gum. Any type of bubble gum. I know some people who go to extreme lengths to chew natural 0-calorie tree bark bubble gum imported from Turkey, and I find that hilarious.

Breaking the fast

The worst meal I used to break a fast was half a jar of pickles. It gave me an intense kidney pain that took hours to clear.

The second worst meal were plain veggie salads. Instant diarrhea.

The third worst meal was plain fruits.

Here is my preferred way. I start with 4 big spoonfuls of yoghurt. Two hours later I move to a regular high carb meal, like a couple of boiled or scrambled eggs with some bread. Or even a hotdog. The only thing I avoid on the first day is salads.

Weight loss

I lose 1.1 lbs of weight per day on average. More if I do light cardio. Measuring my weight every morning is the biggest motivator that keeps me going. Usually on the 3rd day of my fast I have a huge fake weight loss, when I lose about 4lbs, but 3 of these are water weight that comes back within two days of breaking my fast.

Some parting thoughts. During my first fasts I used to sweat the details a lot. Is this going to break my fast? Is that going to trigger an insulin spike? Are these electrolytes too little? Too much? Gradually, I’ve stopped worrying. The human body is very adaptable and forgiving. Experiment and see what works for you.