As a subject matter expert in human physiology, I can provide you with an informed answer to your question. The human body is designed to survive for an extended period without food, but the duration can vary significantly from person to person, depending on factors such as overall health, body fat reserves, and activity levels. When a person stops eating, the body initially uses up its glycogen stores, which are typically enough to sustain it for about 24 to 48 hours. After that, the body begins to break down stored fat for energy, a process known as lipolysis. Fat is a dense source of energy, and the body can survive for an extended period by using it. However, fat alone is not sufficient because the body also requires essential nutrients that are not found in fat, such as certain amino acids, vitamins, and minerals. The 21 days mentioned in the reference to Mahatma Gandhi is an extreme case and not a typical scenario for most individuals. It's also important to note that starvation can lead to serious health complications and is not a recommended method for weight loss or any other purpose. In contrast, the human body is much less tolerant of dehydration. A person can only survive for about three to four days without water, as water is crucial for maintaining bodily functions, including temperature regulation, waste removal, and nutrient transport. In summary, while it's possible for a person to survive for an extended period without food, the lack of water would be a much more immediate threat to survival. read more >>

The human body needs food and water to survive. A human can go for more than three weeks without food (Mahatma Gandhi survived 21 days of complete starvation), but water is a different story. At least 60% of the adult body is made of it and every living cell in the body needs it to keep functioning.read more >>