By Dr. Zachary LaVigne, B.S., D.C.
For most of human history, eating was unpredictable. Sometimes there was food, sometimes there was not. Our bodies evolved to handle those gaps by using fasting as a form of maintenance. Today, with food available around the clock, the digestive system rarely gets a break. That constant intake can wear down the same systems fasting was designed to repair.
When you stop eating for several hours, your metabolism switches gears. Insulin levels drop, signaling the body to stop storing energy and start repairing cells. Inside each cell, a cleanup process called autophagy begins. It means “self-eating,” but it is really self-renewal. Old or damaged components are recycled and replaced with new ones. This improves energy efficiency, reduces inflammation, and strengthens immunity.
Short periods of fasting also affect the production of immune cells. Studies show that fasting can trigger stem cells to create new white blood cells, giving your immune system a fresh supply of defenders. Once you resume eating, those cells are ready to protect you from infection. It is like a reboot for your internal defense network.
You do not need long fasts to see benefits. A common approach is intermittent fasting, which limits eating to an eight or ten-hour window each day. For example, you might eat between 10 a.m. and 6 p.m., then let your body rest from food overnight. During that time, inflammation decreases, the liver clears toxins, and hormone levels rebalance. Many people notice better digestion, sharper focus, and steadier energy once they adapt.
Fasting also calms the nervous system. Without constant digestion, blood flow shifts toward repair and restoration. The body becomes quieter, and that quiet can feel surprisingly peaceful. You are not starving; you are allowing your body to perform the kind of maintenance it rarely gets the chance to do.
Of course, fasting is not for everyone. People with certain medical conditions, those who are pregnant, or anyone with a history of disordered eating should talk to a healthcare provider first. For most healthy adults, though, mild fasting is safe and beneficial.
The modern world has taught us to eat constantly. Breakfast meetings, snacks at our desks, late-night bites. This constant grazing keeps insulin high and prevents the body from ever shifting into repair mode. Fasting restores contrast. It gives your immune system a pause to refresh itself.
When you feel that familiar urge to snack just because food is nearby, remember that your ancestors often went hours without eating and thrived. Fasting is not punishment; it is a rhythm. It reminds your body that it already knows how to heal itself, as long as you give it time to do the work.