Extended Fasting Fasts beyond forty-eight hours, where the metabolic picture changes qualitatively rather than by degree — deep ketosis, sharply raised growth hormone, and autophagy running at rates shorter fasts do not reach. Also where the risks become real: electrolyte depletion, refeeding syndrome, and medication interactions that need supervision. Fasting-Mimicking A calorie- and protein-restricted eating pattern designed to trigger some of the fasting response while still eating. The appeal is adherence; the open question is how much of the benefit survives the compromise. These pages cover the research behind the approach and how it compares to fasting outright. Intermittent Fasting The most studied and most misunderstood of the fasting patterns. Most of its benefit comes not from the eating window itself but from what falls out of the diet when the window closes — the evening snacking, the sweetened drinks, the constant low-grade insulin signal. These pages cover what the trials actually measured and where the effect sizes are smaller than the enthusiasm. OMAD One meal a day: the whole day's food inside roughly an hour, and a fast of twenty-three. It is the simplest fasting pattern to follow and the hardest to do well, because a single sitting has to carry a full day's protein and micronutrients — which is where most people running it long-term quietly come unstuck. These pages cover who it suits, how to build the meal so it is sufficient, and the signs that it has stopped serving you. Time-Restricted Eating Eating within a consistent daily window, usually eight to twelve hours, aligned with daylight. The mechanism is circadian rather than caloric: the same meal produces a different glucose and insulin response at eight in the morning than at ten at night. These pages cover the timing research and how much of it holds up outside the lab. Water Fasting The most demanding protocol and the one with the thinnest modern evidence base relative to its reputation. Much of what is claimed for it comes from historical clinical practice and small studies rather than controlled trials. These pages cover what is known, what is extrapolated, and the situations where attempting it unsupervised is genuinely dangerous.