Help

Fasting

Updated March 16, 2026

This content is for informational purposes only and is not a substitute for professional advice.

Fuel includes a fasting experience on Today with a live tile, zone progress, a detailed timeline, notification controls, and dedicated achievements.

The fasting tile on Today

The fasting tile shows your current fasting state in real time. It displays elapsed time, your current zone, and progress toward your next zone milestone.

The tile updates live so you can check your fast without navigating away from Today.

Fasting zones

Fasting zones mark physiological milestones as your fast progresses. Each zone represents a different stage.

Progress through zones is shown visually on the tile and in the detailed timeline so you can see where you are and how far the next zone is.

Fasting timeline

The fasting timeline provides a detailed view of your current and past fasts. It shows when you started, when you broke the fast, total duration, and which zones you reached.

Use the timeline to review patterns over time and understand how your fasting windows relate to your meal timing and overall nutrition plan.

Notification controls

Fasting has its own notification controls so you can receive alerts for zone transitions and fasting milestones without adding noise to your other reminders.

Configure fasting notifications separately from your Smart Notifications settings.

Fasting achievements

Fasting includes 11 dedicated achievements that reward consistency and duration milestones. These appear in your Badges and Achievements collection alongside movement and other badge categories.

Getting started with fasting

Fasting tracking activates automatically based on the gap between your last meal and your next. You do not need to manually start or stop a fast — Fuel infers the window from your food logging timestamps.

Log meals consistently so the fasting window calculations stay accurate. If a meal is logged late or on the wrong day, it can shift the apparent fasting window.