Revision #124

'''Intermittent fasting''' means choosing ''when'' you eat rather than ''what'' you eat. Loopa times your eating window, shows what your body is doing as the hours pass, and keeps a history so you can see whether it is actually working for you.

'''Where to find it:''' '''Log → Fasting''' on [[Using mobieusHealth on desktop|desktop]]; [[The Fasting timer|the Fasting timer]] on [[Using the iOS app|iOS]] (with a [[Fasting Live Activity|Live Activity]] on your lock screen); a background timer on [[Using the Android app|Android]] that keeps counting with the app closed. Fasting is an '''opt-in tracker''' — switch it on in [[Settings]] and it appears in your menu.

== What fasting actually does ==

Be clear-eyed about this, because the internet is not. Fasting is a '''tool for eating less without counting every bite'''. Most people who lose weight on a fasting schedule do so because a shorter eating window means fewer calories, not because of anything magic about the clock. Trials that match calories between fasting and ordinary calorie-cutting tend to find similar results.

That is not a knock. "Eat between noon and 8pm" is a rule you can follow without a spreadsheet, and a rule you will follow beats an optimal plan you won't. If that is you, fasting is a fine choice. If skipping breakfast makes you ravenous by 2pm and you eat more overall, it is the wrong tool and there is no prize for persisting.

Some people also report steadier energy and less snacking once adapted. Others feel foggy and irritable. Both are normal — you learn which you are by trying it, which is what the history in this app is for.

== Choosing a window ==

'''Start gentler than you think.''' The most common mistake is jumping to 20:4 on day one, feeling awful, and concluding fasting doesn't work.

* '''12:12''' — a 12-hour overnight fast. Barely a diet; most people already do this. Good week one.
* '''14:10''' — the first real step. Push breakfast an hour or two later.
* '''16:8''' — the popular default. An 8-hour window, e.g. noon to 8pm.
* '''18:6''' — for people already comfortable at 16:8.
* '''20:4''' — a short window. Getting enough protein becomes genuinely hard here.
* '''OMAD''' — one meal a day. Very difficult to hit protein and micronutrient needs. Not a beginner's setting.
* '''Custom''' — set your own target in hours.

Move up only when the current window feels easy for a week or so. There is no extra credit for a longer fast you dread.

== Getting through the fast ==

* '''Drink.''' Water, black coffee, plain tea. Thirst is regularly mistaken for hunger. See [[Hydration]].
* '''Salt matters.''' Headaches and light-headedness in the first week are usually fluid and electrolytes, not starvation.
* '''Hunger comes in waves.''' It rises and passes rather than climbing forever. The 20 minutes you think you can't survive is usually the peak.
* '''Keep busy through the hard hour.''' For most people that is the hour before the window opens.
* '''Anything with calories ends the fast.''' Milk in coffee, "just a bite", most gum. The app's stage clock assumes you actually fasted.

== Breaking a fast well ==

This is where fasting most often falls apart. A 16-hour fast followed by 1,800 calories of whatever is within reach nets you nothing.

* '''Lead with protein''' — eggs, fish, meat, dairy, beans, tofu. It blunts appetite better than anything else. See [[Macronutrients explained]].
* '''Add fibre and volume''' — vegetables, fruit, whole grains. They fill you on fewer calories.
* '''Eat slowly.''' Fullness signals lag by about 20 minutes; eat fast enough and you'll pass "satisfied" without noticing.
* '''Plan the first meal before you're hungry.''' Decisions made at hour 16 are bad ones. [[My Meals]] and [[Meal planner|the Planner]] exist for this.
* '''Don't "earn" a binge.''' If a fast reliably ends in one, the window is too aggressive.

== Fasting stages ==

As the hours add up the stage label moves through four phases:

* '''Fed''' — the first few hours after eating.
* '''Early fast''' — from about 4 hours.
* '''Fat-burning''' — from about 12 hours.
* '''Ketosis''' — from about 16 hours.

'''These are approximations on a clock, not measurements of your body.''' The real timings shift with your last meal, your activity, and you. Nobody is reading your blood. Treat them as a rough narrative, not a readout. If you want to know your actual ketone or glucose response, that needs testing — see [[Blood glucose]].

== Streaks and history ==

Finish fasts to build a '''streak'''. A weekly mini-chart shows your fasting hours day by day, and the history logs each fast with whether you met your target.

Use the history honestly. If four weeks of good streaks hasn't moved your weight, your eating window is not the problem — your total intake is. Check [[Calorie and macro tracking]] and [[Weight forecast|the forecast]] before you shorten the window further.

== Fasting and training ==

Light and moderate exercise while fasted is fine for most people. Hard or long sessions usually go better with food beforehand, and strength training in particular benefits from protein reasonably close to the session. If you train early, an eating window that starts at noon may be fighting you — shift the window rather than the training. See [[Diet and exercise]].

== The AI fasting coach ==

When mobieusAI is on, [[Help Me]] can suggest a fasting window that fits you, reading your fasting history, recent vitals, weight and health notes, and explaining its reasoning, what to expect, and the cautions. It will recommend a gentler approach — or none at all — where fasting is not a good idea.

== Who should not fast ==

Skip fasting, or talk to a clinician first, if you:

* are '''pregnant or breastfeeding'''
* have '''diabetes''' or take glucose-lowering medication — especially insulin or sulfonylureas, where fasting risks hypoglycaemia
* take '''medication that must be taken with food''', or on a fixed schedule
* have a '''history of disordered eating''' — rigid food rules and timed restriction can restart it
* are '''under 18''', underweight, or recovering from illness or surgery
* have a condition affecting blood pressure, kidneys or liver

Stop and eat if you feel faint, shaky, confused, or your heart is racing. That is information, not failure.

== See also ==
* [[The Fasting timer]]
* [[Fasting Live Activity]]
* [[Healthy eating]]
* [[Understanding calories]]
* [[Macronutrients explained]]
* [[Healthy weight loss]]
* [[Hydration]]
* [[Keto diet]]
* [[Diet and exercise]]

''Wellness tracking, not medical advice. Everything here is informational only — talk to a qualified healthcare professional before you change your diet, exercise, supplements, or medication.''

[[Category:mobieusHealth]]
[[Category:Goals and progress]]