One of the most popular new methods of weight loss is “Intermittent Fasting” or IF. Basically, this involves not eating only foods or ‘bulletproof coffee’ for 12-16 hours. Studies have shown that this can be an effective method of weight loss and stimulate beneficial endocrine processes. So what’s the problem?
Well, most of the studies have only been done on men. Due to hormonal differences, women react very differently to calorie restriction. In fact, following the IF protocol can lead women to GAIN weight, disrupt their periods and trigger uncontrollable hunger cravings!
In order to protect any potential fetus, women’s hormones are exquisitely sensitive to changes in the availability of food. If women detect a “starvation state,” their bodies will do everything possible to retain fat. Continued fasting can trigger menstrual disruption, cause sleep issues, low energy, irritability and acne all due to the hormonal changes triggered by lack of food. After starting the slide into a starvation state, women may incur overpowering hunger as the body is trying to store fat to prevent starvation, possibly leading to weight gain.
This article gives a deep dive into a review of the science, which is sparse. What does exist clearly communicates women’s metabolisms respond very differently to calorie restriction and fasting and more research is necessary.
In conclusion, although some women may be able to benefit from fasting while avoiding most of the side effects, many others will not and may be doing harm to their metabolisms. Instead of IF, I would encourage women to try to eliminate sugar and processed foods from their diet and do more resistance training; not only can these help with weight loss, but have numerous other health benefits with none of the potential risks associated with fasting. Second, be wary of grandiose claims of weight loss magic bullets (especially when advocated by a man with a product to sell). Although their advice may be applicable for men, most likely they haven’t accounted for how to tailor their advice to women.