u/andtitov

Hey folks! A new version of the Fasting Center app just went live on both app stores. Everything below is already in the app - update and it's yours. Most of it came straight from your comments and DMs on the last two posts

• Import from Easy Fast - the most requested feature so far, bring over your full history in Settings.
• Export to Excel - download all your data anytime as a spreadsheet.
• Widget options (iOS) - edit Widget now offers time elapsed, time left, % elapsed, or % left.
• Blood glucose in mg/dL or mmol/L - pick your unit in Settings.
• Fast syncs across devices - start on one device, see and stop it on another.
• Edit the end time when ending a fast - set the real time you started eating, right on the end screen.
• Your plan sticks - finish a 19:5 and it stays selected for next time.
• More Dashboard stats - fasting-hours chart with your goal line, plus tap-to-switch summary tiles.
• Others - steps tracking (iOS), a reorganized Dashboard, and durations as "2d 3h" or "51h" - your choice.

Still free, no ads, no paywall, no subscription 😊

Everything above is live today - just update the app. A few more of your requests are queued for the next version. If there's something you wish your fasting app did, tell me in the comments or DM me. Happy fasting!

Hey immortalists! I finished my annual 10-day water fast on Aug 6 and then 12-day refeeding yesterday. So, I wanted to share my data with the community, if someone wants better understand extended fasting

The fast

• Weight: 161.6 to 149.7 lbs, down 11.9 lbs
• Ketones: 0.4 to a peak of 7.9 mmol/L, the deepest ketosis I've ever recorded, ended at 5.9
• Glucose: lived in the 60s-70s all week, bottomed out at 54 on day 8, finished at 65
• RHR held 42-50 bpm the whole fast, HRV in the 34-48 ms range
• Low hunger, sharp mind, steady energy through day 10. Ramping up electrolytes mid-fast helped a lot

The refeed

• Scale weight: 149.7 back up to 158.8 lbs
• Dexa: Fat tissue - 24.3 lbs pre-fast, 19.0 at end of fast, 19.7 now, only 0.7 lbs of fat regained
• Lean tissue: 132.9 pre-fast, 125.1 at end, 134.4 now, fully recovered plus 1.5 lbs
• Body fat %: 14.8 pre-fast, 12.2 now

Net result - down 4.6 lbs of fat, up 1.5 lbs of lean. The weight regain was glycogen, water, and muscle, and just a bit of fat. The scale exaggerates fat loss during the fast and exaggerates fat regain during refeeding.

Happy to answer any questions. And if you're mid-fast right now, good luck, you've got this!

Hey folks! Since I got so many comments about lean mass loss during my 10-day fast (data dump posted last week), here's an update - got another Dexa today, 12 days into refeeding. My lean mass fully came back and even brought a bit extra 😊

• Lean mass: 132.9 pre-fast -> 125.1 right after the fast -> 134.4 today, all 7.8 lbs came back, plus 1.5 lbs above my pre-fast baseline
• Body fat: 24.3 pre-fast -> 19.0 post-fast -> 19.7 today, so almost all the regained weight is lean tissue and glycogen, not fat
• Total weight: 164.1 pre-fast -> 151.0 -> 160.9 over 12 days of refeeding

So, the lean mass you lose during an extended fast comes back fast with refeeding. The body is not stupid to burn precious muscle during scarcity when it has body fat stored specifically for that situation. My lean mass actually overshot the baseline this time, though honestly I was probably too aggressive jumping back into strength training. Intensity-wise (strength training, running, playing soccer) I was back at pre-fast levels by day 7 of refeeding.

Hope this helps dissolve the concern that extended fasting is that detrimental to muscle. I also saw a post asking how much to fast - my protocol is one extended 7-10 day fast once a year plus daily IF (often dirty IF). Happy to answer any questions!

Hey folks! This morning, after a 10-day water fast and 10 days of refeeding, I did my final weigh-in on my floor scale. Net-net - I lost 3.2 lbs of total weight, but more interestingly, 4.1 lbs of body fat (22.8 to 18.7) while gaining 1.3 lbs of lean mass (138.8 to 140.1). If that holds up, it would be awesome!

Tomorrow I'll do my final post-refeeding DEXA scan for a more accurate view of the weight loss and body recomposition.

Hey folks! Since so many of you asked for new features and fine-tuning after my post last week, here's a quick update on the Fasting Center app

• BMI card - add your height in the new profile section and see your BMI trend next to your weight in the Dashboard
• The extended fast calculator now goes to 40 days (vs 21 days before)
• Metric by default - kg/cm out of the box outside the US, Liberia and Myanmar, basically for 95% of people worldwide 😊
• 24-hour time - follows your system setting
• Ring % of goal - tap the timer to switch between elapsed time and percent of your goal
• Home screen widgets (small and medium) and dark app icon for iOS

It's free, no ads, no paywall, no subscription.

I know several people already suggested new features - I'll look into those requests. If there's something you wish your fasting app did, tell me in the comments or DM me. Happy fasting!

Hey folks! Last week I posted that I finished my 10-day water fast. I finally collected and updated all charts, so here's the full data. Measured with a Keto-Mojo 3 times a day, smart scale, and an Oura ring.

• Weight: 161.6 to 149.7 lbs, down 11.9. Dexa - 13.1 lbs total, 5.3 lbs of fat. Five days into refeeding I'm back up 7 lbs, that's water and glycogen, not fat
• Ketones: 0.4 to a peak of 7.9 mmol/L, hit twice, dropped below 1.0 within 24 hours of the first meal
• Glucose: 60s-70s most of the fast, low of 54 on day 8. First refeed meals spiked me to 132 and 137, way above my normal, go easy on carbs early
• RHR and HRV: RHR held 42-50 bpm, HRV dipped to 34 ms mid-fast, rebounded to 48 by the end
• Sleep: mostly stable, with some ups and downs

Also, I did full blood panels before the fast and at the end of it, and will do one more after refeeding. Will share the full 3-way comparison in a separate post.

The biggest helper - ramping up electrolytes (reduced cramps) and switching to morning intake (reduced night urination) mid-fast. Happy to answer any questions. And if you're mid-fast right now, good luck, you've got this!

Hey folks! I completed my 10-day water fast yesterday, shared my preliminary result and a common question I hear is how I managed my electrolytes during the fast. So, let me share my approach, as this time I made 2 meaningful changes that positively affected my fasting experience.

First, I tracked all potassium and magnesium intake in a spreadsheet. For sodium, I assumed I got enough through pink salt and didn't track it separately. My two sources, taken 3-4 times a day, are Ultima packets with 250 mg potassium, 100 mg magnesium and potassium citrate capsules with 99 mg potassium.

Two changes I made after day 5

• Increased the total intake to fight cramps. Cramping started creeping in mid-fast, and bumping up the doses took care of it.
• Moved all doses before 3 pm (I know, I should have figured that out earlier 😊). I originally spread them evenly through the day and was getting up 3 times a night to urinate. Front-loading electrolytes brought it back down to normal.

Both worked really well. This was probably my easiest 10-day fast so far, and I credit a lot of that to getting electrolytes right instead of treating them as an afterthought.

Just completed my annual extended fast, it was 10 days this year. Dexa shows 13.1 lbs of total weight lost, 5.3 lbs of it body fat. I captured a ton of data including blood work and will post it later.

This was probably the easiest fast I've ever done. Practice makes perfect, and ramping up electrolytes mid-fast helped a lot.

Happy to answer any questions. And if you're mid-fast right now, good luck, you've got this!

Hey folks! Follow-up to my day 8 post. A few people asked if the ketone climb looked unusually steep, so I put my older fasts on the same axis, plotted by hour instead of by date.

It is steep, but it's my normal. This fast tracks almost exactly on top of my 10-day fast in 2025, and matched the 7-day fast for the first 130 hours. The one outlier is my 9-day fast, slower and lower throughout - I was quite inactive during that fast.

Ending tomorrow morning at hour 240, then refeeding. As always, this is N=1 and responses to extended fasting vary widely between individuals and even between fasts for the same person.

Hey folks! Quick follow-up to my post from 12 days ago about Fasting Center. At the time it was iOS only, and the most common question by far was "when Android?"

Android is here. Same app, same features

• Fast timer with fasting stages on the ring
• Log for fasts and biometrics (weight, body fat, waist), with notes and mood
• Calculator connected to your real data - projected vs actual weight loss, daily breakdown by tissue type
• Health Connect sync

Since launch it's been used by hundreds of people, and I've used it myself - first on my regular IFs, and now on the 10-day fast I'm tracking in the app.

Still completely free, no ads, no paywall, no subscription. You also sent me a great list of feature requests. They're coming in the next release. Thank you for your patience, and keep the feedback coming - I read everything and ship fixes fast!

Hey folks! I'm on day 9 of a 10-day water fast (water and electrolytes only) and wanted to share my numbers with the community, since many here are curious how the body responds to extended fasting.

• Weight: 161.6 to 150.5 lbs, down 11.1 lbs, roughly 4.8-5.5 lbs of it fat
• Ketones: 0.4 to 7.2 mmol/L, peaking at 7.9 yesterday. All endogenous, no exogenous ketones or MCT
• Glucose: settled into the 60s-70s with a low of 54 last night, and energy stayed stable throughout
• RHR: steady at 45-50 bpm all 9 days
• HRV: drifted down from 45 to 34 ms under the metabolic stress, then rebounded to 39
• Subjective: hunger is basically gone, mental clarity is high, I'm in cruise mode

I test glucose and ketones 3 times daily with a keto-mojo and log everything. As always, this is N=1 and responses to extended fasting vary widely between individuals and even between fasts for the same person. I hope it gives a good perspective how fasting works, happy to answer any questions!

Hey folks! Day 9 update from my 10-day water fast (started 7/27 and targeting to end on 8/6)

• Weight: 161.6 to 150.5 lbs, down 11.1 lbs so far, including 4.8-5.5 lbs of fat. I feel that the Fasting Center app's projections are more accurate than my weight scale
• Ketones: 0.4 to 7.2 mmol/L, peaking at 7.9 yesterday, deepest ketosis of the fast
• Glucose: holding low, hitting a low of 54 last night and 67 this morning
• Sleep and readiness: sleep scores dipped into the low 60s, which is typical for me late in a long fast, but readiness is holding strong at 77-89, that's really good for me
• Feelings: yesterday was a rough day - I felt great in the morning, went to the gym (10 mins cycling, 30 mins running and 20 mins steam room) and in the evening I realized it was a bit too much. I felt weak and sluggish yesterday night.

8 full days done, 2 to go. Who else is on an extended fast now?

Day 7 update from my 10-day water fast (started 7/27 and targeting to end on 8/6)

• Weight: 161.6 to 152.7 lbs, down 8.9 lbs so far, including 3.7-4.7 lbs of fat
• Ketones: 0.4 to 5.4 mmol/L, peaking at 5.7 yesterday, deep in fasting ketosis
• Glucose: holding low, hitting a low of 59 last night and 74 this morning
• Feelings: still in cruise mode. Energy is decent, hunger is low, and mentally I feel good

Pretty cool that weight and fat loss projections are close to actual measurements.

6 full days done, 4 to go. Who else is fasting now? Any data can you share?

24 years vs 49 years 😊 Just to clarify - I wasn’t a couch potato back then. I was actually the captain of my university’s varsity soccer team in Moscow, so I was pretty tough. Though looking back, I can see I was carrying some extra fat 😊

Day 5 update from my 10-day water fast (started 7/27 and targeting to end on 8/6)

• Weight: 161.6 to 155.5 lbs, down 6.1 lbs so far, including 2.5-4 lbs of fat
• Ketones: 0.4 to 4.5 mmol/L, staying firmly in fasting ketosis
• Glucose: continuing to trend down, hitting a low of 61 yesterday and 67 this morning
• Feelings: in cruise mode. Energy is decent, hunger is low, and mentally I feel good

 

Four full days done, six to go. I hope this helps, and happy fasting to everyone who’s fasting!

Day 4 update from my 10-day water fast

• Weight: 161.6 to 156.2 lbs, down 5.4 lbs so far. Fat is down by 2.7 lbs, a bit optimistic, but I am ok with that.
• Ketones: 0.4 to 4.3 mmol/L, now firmly into fasting ketosis.
• Glucose: mostly trending down, from the mid-80s to 69 last night, then back to 76 this morning.
• Feelings: getting into cruise mode. Energy is decent, hunger is low, and mentally I feel good 😊

Day 3 is usually my hardest day, and this fast followed the same pattern. Once ketones crossed 3, things got noticeably easier. Happy to answer questions about the protocol!

I am not on TRT or any medication, just natural level.

Is it something that I am doing right? Or it's just genetic?

Day 3 update from my 10-day water fast, started 7/27 and targeting to end on 8/6.

• Weight: 161.6 to 158.6 to 159.3 lbs. So, it went up 0.7 lbs in one day - water retention, nothing else it can be on zero calories.
• Ketones: 0.4 to 2.6 mmol/L, steady climb, ketosis is kicking in.
• Glucose: mostly mid-80s, then a random 122 post-gym spike yesterday at 1pm, best guess - cortisol/adrenaline response. Back down to 77 this morning.
• Feelings: feel ok, focusing on my things.

Day 3 is usually my hardest day, and once ketones cross 3, it gets much easier.

Happy to answer questions about the protocol 😊