Of all the topics I cover, fasting is easily one of the most polarizing. But it’s also one I feel strongly about—because the science is clear, and I want to help women avoid its many pitfalls. While some women do say they feel good when fasting, the long-term research tells a different story. Let’s break down why fasting simply doesn’t support active women.
Women Are Not Small Men
For far too long, women have followed health and fitness advice based on male physiology. Whether it’s for training, weight loss, or even medical treatment, most of the guidelines out there come from research done on men.
Fasting is no different. While some studies show benefits for active men, the data tells us that fasting often has the opposite effect for active women. Research shows definitively there are sex differences in energy metabolism and metabolic homeostasis, which is why women (as compared to men) are more efficient in conserving energy stores (aka fat) and proteins (for fuel, not to conserve lean mass) in times of food scarcity or prolonged exercise.
(Quick clarification: I’m talking about active women—those who exercise with intention. For sedentary populations, fasting may offer some benefits. But for active women, it often leads to more harm than good.)
