Fasting: How many days can someone go without eating until they die of hunger?

Everyone knows that the consumption of food and water is essential for human life. Although the human body cannot survive long without water, it can survive several weeks without food. A prolonged period without eating, however, can lead to hunger and malnutrition. How long we can survive without food depends on a variety of factors and there is no definitive time frame for starvation. But evidence suggests it only takes about eight hours without eating for our bodies to change the way it operates. So how long can the body live without food?