What happens to the body when a person goes on a water fast?

During initial days of a water fast, body depletes glycogen stores, leading to fat utilisation for energy. "This can result in rapid weight loss...and muscle mass...as...body also breaks down protein for essential functions," said consultant physician Dr Haricharan G. Extended fasting triggers ketosis, where body converts fat into ketones for energy. Extended fasting can lead to deficiencies.