Metabolic Switch
The transition from burning carbs to burning fat.
This switch happens when glycogen stores are reduced and the body needs another fuel source. The timing varies depending on your eating habits and activity level. Early in the process, you may feel tired or distracted as your body adjusts. With repetition, the transition becomes smoother and less noticeable.
Related Topics
Fasting
Fasting changes the structure of eating. This page covers how it works for weight loss, the difference between intermittent and extended approaches, and where it fits in a sustainable method.
Intermittent Fasting
How intermittent fasting actually works, what changes inside an eating window, and where it fits alongside calorie deficit and walking for sustained weight loss.
Related glossary terms
Action Loop
Repeating fasting, calorie control, and walking as the core routine.
Eating Window
A defined time period when food is consumed.
Fasting Arc
The predictable progression of physical and mental states during a fast.
Fasting Window
The period where no calories are consumed.
Fat-adapted State
A state where the body relies more on fat than carbohydrates for energy.
Fat-Burning Switch
The point where fat becomes the primary fuel source after glycogen depletion.
Momentum Window
The period after a fast where fat burning remains elevated and hunger is reduced.
Refeed
The phase of eating after fasting where food and glycogen return.