Before I talk about fasting and how it boosts your metabolism, I want to bring up something I’ve talked about in the past (quite recently actually), and that is “brown adipose tissue”.
Human beings (and many animals) have 2 types of fat (adipose tissue): white and brown.
White adipose tissue is the “fat” that most people think about: it’s the unhealthy kind of fat that makes us, well, look “fat”, produces inflammatory cytokines (inflammation throughout the body), and increases risk of all sorts of diseases.
White adipose tissue is metabolically inactive: in other words, it doesn’t “burn” energy, it just stores is.
Brown adipose tissue / brown fat (BAT), on the other hand, is a different type of fat: it is “metabolically active”: this means that it actually “burns” energy.
The main reason BAT burns energy is because its function is to “keep us warm”.
This is why it’s most active when we are exposed to cold temperatures.
In fact, we find the most BAT in people living in the coldest climates, such as Alaska, and inside the Arctic Circle (e.g. Eskimos and Inuits).
In a recent article, I talked about new research which shows that combining green tea extract with cold exposure increases the production & activity of BAT in humans, which could result in a higher metabolism and more fat loss.
This new study published in Cell Metabolism has revealed some new and interesting findings:
“Intermittent Fasting Promotes White Adipose Browning and Decreases Obesity by Shaping the Gut Microbiota”.
In this study, they discovered that Every Other Day Fasting (EODF) stimulates the conversion of white adipose tissue (white fat, the find bad kind) into brown adipose tissue (the good kind).
In addition, they noticed that people on an EODF way of eating saw improved body composition, insulin resistance, and liver function.
It does this by increasing the metabolism of mitochondria, the tiny power plants inside your cells responsible for energy production: this means that the more BAT you have, the higher your metabolism.
Of course, this flies in the face of the common “gym bro” advice of “eat 6 meals a day to boost your metabolism”, which has been shown through hundreds of studies over the years to be completely FALSE and terrible advice when it comes to fat loss.
What is EODF? As the name implies, it means fasting “every other day”.
So on one day you eat normally, and on the second day you either completely fast (i.e. drink only water, tea, and consume 0 calories) or (less ideally) eat less than 300-400 Calories.
Now of course, this adds to the TONS of other proven health benefits of fasting, including improved gut function, liver function, insulin sensitivity, anti-ageing, anti-inflammation, immune system support, and even clean-up of cancerous cells by the body.