A 3-day water fast is often seen as a way to lose weight quickly—but there’s more going on beneath the surface than just a drop in body weight. For many, it’s a method to reset their eating habits, cut down calorie intake, and explore the potential health benefits of water fasting. By drinking only water for 72 hours, your body enters a fasting period that shifts your metabolism. You start to burn fat more efficiently, insulin levels drop, and the body begins to repair old or damaged parts through natural processes. This can lead to short-term weight loss and reduced water weight, along with clearer thinking and better control over blood sugar levels. But while the idea of significant weight loss in just three days is appealing, there are risks. Things like electrolyte imbalance, low blood sugar, mood swings, and changes in systolic blood pressure can all happen, especially without proper medical supervision. If your goal is to burn fat or improve insulin sensitivity, it’s still important to be aware of what your body goes through during a fast like this. Water fasting may have several health benefits, but it’s not a quick fix. The effects depend on your current health, how much weight you want to lose, and what you do after the fast. Keep reading to see what a day water fast really does to your body, what the potential risks look like, and how to do it in a way that supports long-term well-being.