New clinical trials from the NEJM, Harvard, and the University of Colorado finally pit intermittent fasting against caloric restriction in humans — here is what they actually found, and what a doctor thinks it means for you. For years, the debate over intermittent fasting felt like a religious war. Fasting advocates insisted that eating reshapes your metabolism in ways that calorie math cannot capture. Conventional dietitians fired back that it is still just a calorie deficit, dressed up differently. Both sides had animal studies, observational data, and a handful of small, short-term trials to wave at each other. What neither side had, for a long time, was gold-standard clinical evidence. Properly randomized, properly powered, and properly long. That changed between 2022 and 2025. A cluster of major RCTs and large-scale meta-analyses, some from Harvard and some from the University of Colorado, finally put both strategies through rigorous head-to-head testing in humans.…