Fasting

Many GLP-1 users naturally drift into intermittent fasting because appetite is suppressed enough to skip breakfast. This system tracks scheduled fasts, one-off fasts, and shows where you are in the current window.

What you see

When enabled, the Log page shows a fasting banner with:

• Current state — eating, fasting, past goal, etc.
• Elapsed / remaining time.
• Current stage — Burning carbs / Switching to fat / Ketosis / Deep ketosis.
• Progress bar if a planned end is set.

The banner is always live. It updates every minute.

Setup

1. Profile → Tracking → Fasting.
2. Enable.
3. Pick a protocol:
   • 14:10 (14h fast / 10h eating window)
   • 16:8 (most common)
   • 18:6
   • 20:4
   • OMAD (one meal a day, 23:1)
   • Custom — set your own duration.
4. Pick a schedule kind:
   • Daily — fast every day.
   • Weekly — different rules per weekday (e.g., 16:8 weekdays, no fast weekends).
5. For each rule, pick a start time (e.g., "fast starts at 20:00").

Save.

Schedule types

Daily

A single fast pattern repeats every day:

Start: 20:00
Duration: 16 hours → ends 12:00 next day

Eat between 12:00 and 20:00. Repeat.

Weekly

Different rules per weekday. Each weekday gets its own start time and duration:

Mon: 20:00, 16h
Tue: 20:00, 16h
Wed: 20:00, 16h
Thu: 20:00, 16h
Fri: 18:00, 14h (longer eating window for social events)
Sat: (no fast)
Sun: 18:00, 36h (extended weekly fast)

Days you don't list don't have a scheduled fast.

One-off fasts

For irregular fasts that don't fit your schedule:

1. Tap the banner → Start fast now (or pick a future start time).
2. Enter a planned duration.
3. The fast runs alongside (or instead of) your scheduled rule.

If you tap Start fast during a scheduled fast window, the manual start replaces the implicit scheduled fast — useful if your real start time differs from the scheduled one.

Fasting stages

The banner labels your current stage by elapsed time:

Elapsed	Stage
0–11h59m	Burning carbs
12h–17h59m	Switching to fat
18h–47h59m	Ketosis
48h+	Deep ketosis

These are loose consumer-fasting framings, not clinical thresholds. Real metabolic state depends on your last meal's composition, glycogen stores, and individual variation. The labels are useful for narrative; don't make medical decisions based on them.

Notifications

Two notification kinds:

• Fast start — fires when your fast begins (or N minutes before; configurable).
• Fast end — fires when your fast hits its planned end (or N minutes before).

Configure in Profile → Notifications → Fasting.

The notification system uses your timezone (set on profile) to determine when "20:00 daily" actually fires. Daylight saving time is handled by comparing wall-clock minutes, not absolute timestamps — a "20:00" notification fires at 20:00 local regardless of DST jumps.

How fasting affects the simulation

The simulation already accounts for fasted-vs-fed state from your food log timing. The fasting feature adds:

• Explicit fast events in the export and the AI assistant's context.
• Cortisol and growth hormone patterns associated with extended fasts (>16h).
• Insulin baseline shifts during prolonged fasting windows.

If you're scheduled-fasting but eating during the supposed fasted window, the food log overrides — the simulation uses what you actually ate.

Working with day status

A scheduled-fast day with zero food logs is a 0-calorie day. By default the tracked vs untracked days system flags zero-log days as "untracked (forgot)." That's wrong if it was an intentional fast.

To fix:

1. Tap the day in the weekly budget strip.
2. Status: Tracked.
3. Reason: Fasted.

The day now counts at 0 calories consumed against the day's target. Real deficit, properly counted.

Common questions

"What if I break a fast early?" Tap the banner → End fast (or just log food). The fast event records actual end time. Simulation reflects the true duration.

"What about extended fasts (24h+, 48h+, multi-day)?" Use a one-off with a longer planned duration. The "Deep ketosis" stage label kicks in at 48h. Multi-day fasts are tracked the same way; the banner just keeps counting.

"Does the AI assistant see my fasting?" Yes. It can answer "How long has my current fast been?" or "What stage am I in?" or "Did my cortisol pattern change after I started 18:6?"

"Can I disable the banner without disabling fasting?" Yes — toggle "Show on Log page" off. Notifications and tracking continue.

Privacy

Fasting data is included in your export and removed on deletion.

Related

• Tracked vs untracked days — for fasted-day status.
• Endogenous simulation — what fasted state changes in the model.