Ketosis
Ketosis is a metabolic state where the body uses fat as its primary energy source due to low carbohydrate availability.
Ketosis occurs when glycogen levels are low and the body relies more on fat for energy. This can reduce hunger and create more stable energy throughout the day. It is commonly reached through fasting or low carbohydrate intake. Staying in this state depends on maintaining low glycogen levels.
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.

Low-Carbohydrate Diet
How a low-carbohydrate diet can support weight loss when used correctly — without strict keto rules. What changes, what to watch for, and where it fits inside a deficit.
Related glossary terms
Caloric Deficit
A caloric deficit means your body uses more energy than you consume. This is the condition required for fat loss over time.
Carbohydrates
Carbohydrates are a macronutrient used by the body as a primary source of quick energy.
Fat
Fat is a macronutrient that provides a concentrated source of energy at 9 calories per gram.
Fat Oxidation
Fat oxidation is the process of breaking down fat to produce energy.
Glycogen
Glycogen is stored carbohydrate found in muscles and liver that the body uses for energy.
Glycogen Depletion
Glycogen depletion is the process of using up stored carbohydrates in the body.
Glycogen Refill
Restoring carbohydrate stores after eating.
Insulin Response
The body's hormonal reaction to food intake, affecting storage and water balance.