Health
My fat loss experiments with ChatGPT and water fasting
Key Points
Unlike my previous post, 15 years, one server, 8GB RAM and 500k users - how Webminal refuses to die - #3 by laks, this is not a technical one. But this may be more helpful Read with disclaimers: It worked for me, doesn’t mean it will work for you. I’m not a Doctor, just a FOSS dev Sometime in Feb 2026
Unlike my previous post, 15 years, one server, 8GB RAM and 500k users - how Webminal refuses to die - #3 by laks, this is not a technical one. But this may be more helpful
Read with disclaimers: It worked for me, doesn’t mean it will work for you. I’m not a Doctor, just a FOSS dev
Sometime in Feb 2026
Fat loss is something I have been trying for like the last 10 years or so. I tried different stuff like 10k walks, GM diet, IM diet, jumping jacks/cycles, millets, etc. Nothing clicked! I’m not consistent with my efforts. I do a few things and give up when the weighing machine doesn’t show results.
If you have medical issues, please check with your Dr. Don’t trade random strangers’ results for your health.
I was surfing online and came across a post where a guy said he crossed 24hrs while pursuing a 72hr water fast.
I calculated how long it had been since my last food; it was around 15hrs. So I decided, “why not” and tried it. I don’t have any medications or medical conditions. So I continued with the water fast and around the 44hrs mark, I couldn’t hold back my hunger, so I broke it.
Disappointed that the original goal of 72hrs wasn’t met.
I was reading more about 72hr fasting, and I came across a comment which said, “Instead of a single 72hr fast, a rolling weekly fast of 36hrs gave better results.”
So I switched my plan. Instead of a single 72hr fast per month, let me do a weekly 36hr water fast. I switched to ChatGPT for ideas and food suggestions.
I carefully chose a day where I was very unlikely to travel outside: Saturday. I started fasting on Friday at 5pm, taking only water until Sunday 9am (40hrs).
After every few hours, I’ll ping ChatGPT with a prompt like:
“Time is now 9am, Saturday - almost 16hrs into fasting, what’s happening in my body?”
It would come back with my current fasting status, and it was kind of like monitoring logs from a server
When I had a slight headache, it suggested taking a pinch of salt with water for sodium, and it worked. I’m always open-minded and ready to break the fast in case of any new symptoms. Don’t want to take a risk.
My other concern was that I had kidney stone issues, so I was worried whether I would re-introduce that again. But AI told me that drinking 3L of water per day is good enough and dehydration is a major reason for kidney stones.
Around 28hrs, it will be Saturday night, so I’ll go to bed early to avoid hunger clashes. In the morning, I’ll usually wake up without any hunger and feel better. When I’m about to break my fast on Sunday morning, I’ll check with ChatGPT about the best way to break the fast.
Because I put so much effort into the last 40hrs, I don’t want to mess it up. So it gave me fiber followed by protein-rich foods.
ChatGPT prompt: “Now the time is Sunday 9:00am, I plan to break my 40hr water fast, tell me how to do it properly”
Then, with my next 40hr fast, I planned how to start the fast in a proper way. So ChatGPT helped again. The last meal should be protein-rich instead of a carb-heavy meal, which will ease the hunger around the 24hr mark.
So I did 16 x 40hr fasts over 4 months. The result is quite nice. I went from obese to overweight. Lost around 14kg and 4.5 inches waist size - that’s approximately 1kg per week.
Why this fit my style
- I spend a lot of time sitting in front of computers.
- On the days I eat something junk food, I go for a 30min or 1hr walk.
- No exercise or 10k steps per day.
- No stress. I can eat ice cream or other things when I want - weekly once. Knowing that it’s water weight and will be gone when I return to my normal routine.
Things to remember
- Always start the fast in the proper way. Friday, no junk, no overeating. Remember, Saturday evening can be easy or difficult based on Friday’s meals.
- Closely monitor your health and track your progress with AI.
- Break the fast properly - don’t eat junk.
So you can see that 3 days a week, we have a clean eating pattern, and the remaining 4 days take a protein-oriented diet. Rarely, some junk food is fine.
What helped
- Use both measurements and the weighing machine. The weighing machine may be stale for a few weeks, but measurements show the progress.
- Have a weight range, not a fixed one. I check the absolute best weight (weight after 40hrs) + 1.5kg is fine for that week. As long as the weight oscillates between that 1.5kg range, you are on track.
- Every week, if you reach a new low after a 40hr fast, it’s good going.
- Again, no stress. Don’t treat it like you are going to lose weight by suffocating yourself. You want to take junk food, take it. Better remember to do basic walking.
- I feel like the brain won’t release fat until it feels it will get food next. The body is not in survival mode, so taking junk, I think, tricks your brain that I’m not stuck in the Sahara desert and helps to lose fat.
Some of my prompts:
“Need to eat outside today. Which items to select for dinner around 7pm”
“Does protein only food cause kidney issues”
“I took like 200g channa is that issue?”
“Time is now 10:30am what’s happening”
“What happens when I drink water, does fat burning process slow down or faster?”
Btw, I did use Claude too, but primarily ChatGPT helped
Btw, I’m available for Lakshmipathi.G.md and https://giis.co.in/foss.html remote contracts or positions, feel free to write to me.