Stage 1 of 6 · 0-4h

Fed · 0-4h

Nothing dramatic is happening yet - and that's the point. The Fed state is where you set up an easy fast.

FedClearingShiftingBurningCleansingRenewing
0-4h
Time window
High
Insulin level
Glucose
Primary fuel
~10-20%
of a 20h fast

The Fed state is the first 0-4 hours of a fast - the window right after your last meal, when your body is still digesting, insulin is elevated, and blood glucose is the primary fuel.

What's happening in your body

After you eat, your digestive system breaks food into glucose, amino acids and fats. Blood glucose rises, and your pancreas releases insulin to move that glucose into cells for energy or storage. While insulin is high, fat-burning is essentially switched off - your body has no reason to tap fat stores when glucose is abundant. This is a completely normal, well-fueled state; you won't feel any of the effects of fasting yet.

Why this stage matters

For most people the Fed state is the easiest part of any fast, which makes it the best time to build good habits. Starting hydrated and calm here pays off in the harder hours to come. FastFlow shows this stage in green on your ring, with a full Body Battery and a steady resting heart rate.

What your biometrics show

Your Garmin or Apple Watch typically shows a slightly elevated heart rate after eating (digestion takes energy) and a high Body Battery. HRV is usually stable. FastFlow reads these live so you can see your body settle as digestion finishes.

What to do during the Fed stage

Breaking your fast? There's no food in this stage - you've just eaten. The goal is to hydrate well and stay relaxed so the transition into the fasting stages is smooth.

Frequently asked questions

How long does the Fed state last?

The Fed state generally lasts about 0-4 hours after your last meal, though a very large or high-fat meal can extend it. FastFlow times it from the moment you start your fast.

Am I burning fat in the Fed state?

No. While insulin is elevated in the Fed state, fat-burning is suppressed because glucose is abundant. Fat-burning begins later, in the Shifting and Burning stages.

What should I do during the Fed state?

Hydrate, take a gentle walk to help manage the post-meal glucose rise, and set up your fast. It's the easiest stage - use it to build the habit.

See the Fed stage on your own wrist

FastFlow reads your Garmin or Apple Watch in real time and shows you exactly which stage you're in - and what to do with it.

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