Already in ketosis: do the timer stages still apply?

The stage names follow the clock

The names on this timer follow the clock only. Fed State, Early Fasting, Fat Burning, Ketosis, Deep Ketosis, Autophagy Window, Deep Fasting, and Prolonged Fast each appear because a set number of hours have passed since the start. The timer measures that time, and it does not measure ketones, glucose, or anything else in the body. The hour marks assume a typical person who was eating carbohydrate before the fast. The full list, with each hour range, is in What the stages on the timer mean.

If you start the fast already in ketosis

Fed State, Early Fasting, and Fat Burning describe the shift after a meal that contained carbohydrate. The body is still using that meal, then drawing more on stored carbohydrate, then using more fat. Those names assume that kind of start.

A 2018 review by Vincent J. Miller, Frederick A. Villamena, and Jeff S. Volek in the Journal of Nutrition and Metabolism defines nutritional ketosis as 0.5 to 3 mmol/L of beta-hydroxybutyrate, a ketone in the blood. That range is their definition, not a target on this clock. Someone who has been eating very little carbohydrate can already be in that state when the fast begins, so Fed State, Early Fasting, and Fat Burning can lag behind. That lag is expected. You can ignore those early names.

How far ahead a person sits varies. The last meal, activity, sleep, and medicines all change it. How long stored carbohydrate takes to run down varies too. The longer account of fuel use is in Metabolic switching & fuel use.

Do not set the start earlier to change the name

The one number the timer measures is hours without food. On the idle clock, I started earlier lets you set the start to an earlier hour, and the fast then begins. While a fast is running, Edit Start Time, next to the started time, changes that start. Both are for the hour you actually stopped eating. The stage name then follows those hours. There is no control that moves only the stage name, and there is no separate timer for a ketogenic diet.

If you set the start earlier so the screen says Ketosis before you have gone that long without food, the hours on the screen are wrong. On a longer fast, those hours are what you use to decide when to stop and how to eat again. Ignoring an early stage name costs nothing. A wrong hour count does.

The later names are still only hours

Autophagy Window, Deep Fasting, and Prolonged Fast change when more hours have passed. They mark a longer fast on this clock. They do not measure autophagy, or any process after it, in you. Autophagy: what it is and what headlines get wrong says human studies have not agreed on an hour when that recycling process switches on.

Starting the fast already in ketosis does not move these names. They still wait for the hours. Whether the processes those names refer to begin any earlier in someone who was already in ketosis is not settled by a source this note can cite, so that question is left open.

A blood test is what shows ketones

A blood ketone meter shows ketones in a drop of blood. This app cannot. The stage name Ketosis on the screen is still only the hours since the start.

Repeated long fasts on a ketogenic diet

Frequent fasts of more than a day, combined with eating days that are already low in calories, add up to a low intake across the week. Protein and minerals on the eating days matter on that pattern. Water and minerals past a day is the note on minerals once a fast passes a day. Who should not fast without a clinician is in Who should be careful with fasting. Dizziness, confusion, fainting, chest pain, and the other reasons to stop are in When to stop a fast.