There have been instances in the news where people have managed to survive for unexpectedly long periods without food. Although these stories may seem unbelievable, the visible effects of fasting become apparent within just a few hours. This raises the intriguing question of how long an individual can actually survive without having access to any food.
The Progression of Starvation
Under normal circumstances, our bodies go through a specific timeline when it comes to dealing with starvation. Initially, food is broken down into glucose, which serves as the primary source of energy for the body. However, when there is a lack of food for an extended period, typically around eight to 12 hours, the body exhausts its glucose reserves.
At this point, the body enters a new phase where it taps into its glycogen stores, which are mainly located in the liver and muscles. These glycogen stores are converted into glucose to provide energy. This process can sustain the body for a couple of days.
After about two to three days of fasting, the liver starts producing ketone bodies as an alternative fuel source. Ketone bodies are synthesized by breaking down the body’s fat stores. This allows the body to continue functioning and provides energy.
If the fasting period continues, and there is no external source of nutrition, the body enters a critical phase. At this stage, the body starts breaking down proteins in all cells into amino acids. These amino acids are then converted by the liver into glucose. The body tries to preserve lean body tissue as much as possible and aims to balance its fat consumption.
However, when the body depletes its fat stores completely, it is left with no choice but to metabolize muscle tissue as it becomes the only remaining source of energy.
The Theoretical Limit of Starvation
Studying starvation presents numerous ethical challenges, resulting in a lack of comprehensive understanding on the subject. Moreover, the duration one can survive without food varies based on factors such as body fat percentage and overall health. Consequently, experts and researchers cannot provide a precise timeframe for how long a person can go without nourishment. Some medical studies suggest that complete starvation may lead to death within 12 weeks, while others propose a maximum of a couple of months. It is crucial to note that starvation can also trigger various life-threatening complications, including liver or heart failure.