When we fast, our body undergoes a series of metabolic changes to ensure that it can continue to function without the usual intake of food.
During the first few hours of a fast, the body relies on its glycogen stores (stored glucose in the liver and muscles) for energy. Once the glycogen stores are depleted, the body starts to break down stored fat (triglycerides) into ketone bodies, which can be used by the brain and other organs for energy. This process is known as ketosis.
As the fast continues, the body’s metabolism slows down to conserve energy. This can lead to a decrease in resting metabolic rate, which means the body burns fewer calories at rest.
It’s worth noting that fasting can have different effects on the body depending on the length and type of fast. For example, intermittent fasting, where individuals fast for a portion of the day or week, may not lead to the same metabolic changes as longer fasts.
It’s important to consult with a healthcare professional before starting a fast, especially if you have any underlying medical conditions or take medication.