The impact of fasting on insulin resistance depends on the method and the individual. Unstructured fasting, extreme calorie restriction, and “compensatory overeating” cycles can increase stress hormones and backfire. In contrast, controlled meal spacing (such as time-restricted eating) may help some people by allowing insulin levels to fall and improving insulin sensitivity. Key criteria are sustainability, sleep quality, preserving muscle mass, and avoiding binge-trigger patterns. If diabetes, hypoglycemia risk, pregnancy, eating-disorder risk, or serious chronic illness exists, fasting protocols should not be used without professional guidance. The most consistent results typically come from a combined system: balanced nutrition, regular movement, and stable sleep.