Intermittent fasting (IF) is very popular at the moment. And it can be useful, and there is some good evidence behind it.

Most of the studies are done on men, and few are done long term on menstruating or menopausal women, who are more sensitive to stress hormones than men.

When you don’t eat in the morning, when your cortisol is naturally high anyway- which is what wakes you up- it can send your cortisol sky high (which gives you a high!). The body produces stress hormones (such as cortisol) so as to release glycogen (glucose) stores in your liver so you don’t starve. In particular it needs to protect the brain.

Intermittent fasting (IF) has become very popular and it is not surprising. It promises better health and weight loss, just by narrowing the hours in the day when we eat. This is something many women have learned to do anyway, by skipping breakfast or other meals to minimise calorie intake and manage their time deficit.

There is also quite a lot of evidence (https://pubmed.ncbi.nlm.nih.gov/34579056/) reported to show that IF can help to improve insulin resistance, lower blood glucose and triglycerides, improve immunity, improve brain health, normalise fat metabolism and improve longevity. One of the problems is that most of the studies done have been done on men, and very few are women specific. Those that are point to women’s metabolisms suffering with IF in ways that are not often discussed. This article goes into this in more depth, but below I discuss the reasons I spend more time discouraging women from IF, than encouraging them.