INTERMITTENT FASTING (IF): SCIENCE-BASED, PLAIN-LANGUAGE Q&A “IF is not a magic diet; it is a timing strategy that often works by helping energy intake and metabolic rhythms align.” Intermittent fasting (IF) restricts eating to defined windows (e.g., time-restricted eating such as 16:8), or uses patterns like 5:2 or alternate-day fasting. Across studies, IF tends to produce weight loss comparable to continuous calorie restriction, with the advantage that some people find it easier to adhere to. Time-restricted eating trials show modest reductions in body weight and fat mass on average, but outcomes depend heavily on overall calories and food quality. Some data suggest improvements in glycemic control, insulin sensitivity, lipids, and inflammatory markers; these changes may appear within a few weeks. IF is not for everyone: pregnancy, breastfeeding, eating-disorder history, diabetes on insulin/sulfonylureas, frail older adults, and certain high-volume athletes may require individualized medical guidance.