When the body experiences hunger or fasting, it doesn’t just slow down — it begins a powerful internal process known as autophagy. This is a natural and essential system that helps the body maintain healthy cells. Autophagy literally means “self-eating.” During this process, cells identify damaged, old, or malfunctioning components and break them down so they can be recycled and reused. This cleanup helps cells function more efficiently and supports overall cellular health. Scientists have known about autophagy for decades, and it plays a role in how the body adapts to stress, aging, and limited energy availability. Fasting is one of the conditions known to activate autophagy. When food intake is reduced, the body shifts its focus from growth to repair. Instead of using energy to process constant nutrients, cells turn inward and begin maintenance work. This includes clearing out misfolded proteins and damaged cell parts that could interfere with normal cell function if they build up over time. Autophagy is especially important for long-lived cells, such as brain and nerve cells, which rely on internal cleanup systems to stay healthy. Because of this, scientists are actively studying the role of autophagy in brain health, aging, and neurodegenerative conditions. Research has shown that efficient cellular cleanup is linked to better cell resilience and long-term function. This process also plays a role in the immune system by helping cells remove harmful material and respond more effectively to stress. Autophagy supports balance inside the body, allowing cells to adapt to changing conditions. While fasting is one way to stimulate autophagy, it is only one factor among many that influence this complex system. Genetics, lifestyle, sleep, and overall health also play important roles. In simple terms, autophagy is the body’s built-in recycling and repair system. By clearing out damaged cellular components and supporting renewal, it helps cells stay healthier and more efficient over time. It is UPVAS in Northern India