I have seen several posts recently about the use of intermittent fasting as a dietary practice. I think it’s important to understand that calorie restriction is part of the bigger picture, and for many, particularly those with fatigue, it may not be the best choice.
One of the only interventions that has been consistently proven to increase lifespan, recognizing that this is primarily based on animal models, is calorie restriction. There is little debate that the flip side of this issue, namely excessive calories with insulin dysfunction, fat deposition, and inflammation is more likely to shorten our lifespan.
Intermittent Fasting Promotes Autophagy
In simple terms, calorie restriction forces us to scavenge our own tissues to keep our brain and heart functioning. We are not getting calories from external sources in our diet and thus only have one option. This process is known as autophagy. Auto- (self); phagy (Latin, to eat).
Fasting for extended periods of time, probably starting at about 16 hours, activates genetic pathways that stimulate the process of autophagy. mTOR and PPAR gamma are two of the primary genes activated. These genes influence factors such as insulin sensitivity and lipid metabolism.
Many women suffer from a condition known as estrogen dominance (ED), which is too much estrogen relative to progesterone. My belief is that ED is a symptom of diverse processes that primarily (but not exclusively) include dysfunctions in cortisol, thyroid, and insulin management.
Calorie Restriction Influences Cortisol, Insulin and Thyroid
Calorie restriction stimulates cortisol release, cortisol inhibits thyroid function and insulin sensitivity, and this may exacerbate the processes that precipitated one’s ED in the first place.
If you are nutritionally sound; if you have a balanced energetic triad of insulin, cortisol, and thyroid; if your gut microbiome is in balance and you have no leaky gut; and finally, if your toxic load is low, IF may be a good intervention to increase your health and lifespan.
I don’t recommend it in a blanket fashion. Too often the practice of intermittent fasting creates more problems than it was intended to solve.