Intermittent fasting is simply the process of going without food (a fast) for a period of time and limiting eating to only certain times. There are many different types of intermittent fasting including an overnight fast, entire days of fasting followed by several days of non-regulated eating. I’ll cut to the chase – the type of intermittent fast that potentially holds the most benefits and is the easiest to follow is fasting 12 – 16 hours overnight. This is far less disruptive than going for entire days without eating. Most people do a good chunk of this naturally by sleeping. Do you really want to be running on empty while going about your day or turn down social engagements because you can’t eat?
How Does Intermittent Fasting Affect Health?
Intermittent fasting has been shown to affect health in 3 different ways. First, by working with our natural circadian rhythms, fasting overnight can cause metabolic changes including improved insulin sensitivity, lower triglycerides, lower systolic blood pressure, lower LDL cholesterol (the bad cholesterol) and weight loss. Our body undergoes many metabolic changes during the course of the day and night. Several studies support the idea that consuming most of your food earlier in the day, rather than later at night, is associated with improved health.
By keeping to a window of time during the day to eat, that can influence lifestyle factors such as eating at night and not getting enough sleep, which has been shown to adversely affect health. If you limit eating to between 8 – 12 hours during the day, this can mean that you are taking in enough energy earlier in the day and not eating in the evening. Many times the food that we eat in the evening and at night isn’t the healthiest.
Finally, intermittent fasting may affect our gut microbiome. Our gut microbiome are all the bacteria and other microbes that live in our digestive tract. The type of microbes in our gut influences everything from weight, chronic disease and mood. Not only do the good bacteria in our gut love pre- and pro-biotics it turns out that they are also affected by Circadian rhythms, just like the other cells in our body. When we feed ourselves during the day and not at night, we are also feeding these microbes on the same schedule which may allow for the regulation of helpful gut microbes and positive effects on our health.
There is evidence that intermittent fasting of 12 – 16 hours overnight may be beneficial for our health. For most people, this simply means not eating anything after dinner. Just as with any other diet change, it is always best to consult with a Nourish RDN first!