I’m 49. And fasting made me fatter…Here’s what the science actually says. Sounds backwards. But after 20 years as a functional nutritionist specializing in women’s metabolic health, I see this constantly in perimenopausal women. When you fast after 40, your body doesn’t respond the way it did at 30. Here’s why: You’re already losing 3 to 8% of muscle mass per decade after 35. Fasting accelerates this. Less muscle means a slower metabolism and more fat storage, full stop. Your thyroid downregulates. When you restrict food, your thyroid slows to conserve energy. Your metabolism is now actively working against you. Your cortisol spikes. Fasting is a physiological stressor. For high-performing women already running on cortisol, it’s gasoline on a fire. Elevated cortisol drives belly fat, disrupts sleep, and creates relentless cravings. Your sleep suffers. A stressed, underfed body cannot repair overnight. Poor sleep then increases ghrelin (your hunger hormone) and decreases leptin (y...