Despite its seemingly recent popularity, the practice of fasting has actually been around for eons. For example, our ancestors would have naturally fasted between hunts as regular food was not always guaranteed (i.e. they didn't have the luxury of refrigerated food storage or 24/7 access to a well-stocked pantry like we do.) Fasting is also a regular part of some religions like Islam, where Muslims observe Ramadan - a month of fasting from dawn until sunset.
Why would anyone want to fast outside of these situations, you ask?
Every single one of us already fast without even thinking about it! That's right, we are all naturally fasting while we sleep (unless you're a sleep-eater.) So what's different about intermittent fasting? Well, it takes things to the next level so to speak, as it's a little more controlled and specific. Basically, you have to put in a little more effort than just going to bed every night!
What is Intermittent Fasting?
Unlike "diets," intermittent fasting isn't focused on what you eat, but rather when you eat.
There are several variations of intermittent fasting, the most common being “time-restricted eating” where you only eat within a designated hour range (e.g. only eats from 10am-6pm).
There is also:
- Alternate day fasting - fast for 24 hours then eat normally for the next 24 hours and so on and so forth
- 5:2 fast - eat normally for 5 days a week and eat very low calories the other 2 days
- Warrior fast - eat only fruits and vegetables during the day and one large meal at night
- Eat-Stop-Eat - one or two days a week you fast for 24 hours and then don't eat anything from dinner one day until dinner the next day
Time-restricted eating is the most common type of intermittent fasting as it is the least extreme and the easiest to follow.
Benefits of Fasting
1. Weight loss
As with any diet modification, the most commonly talked about "side effect" of fasting is weight loss. In a fasting state, the body isn’t getting its regular source of fuel (glucose) so it instead uses the energy your body has stored in the form of fat. Spending more time in a fasted state = more fat stores are burned up for fuel = weight loss.
2. Blood sugar regulation
By burning fat instead of glucose for energy, the body’s blood sugar levels remain stable instead of constantly spiking up and crashing down as occurs when eating glucose containing or glucose forming foods.
3. Increases energy
This one goes hand in hand with the blood sugar regulation because when our blood sugar is constantly spiking and crashing, so is our energy. Alternatively, when we are burning stored fat for fuel in a fasted state, our energy is more stable as a result of our stable blood sugar.
4. Appetite regulation
More stable blood sugar means you’re not craving that quick glucose hit every few hours for energy, which means more stable appetite in turn. Fat also has more calories than glucose (carbs), which means using fat for fuel is more sustainable for our body in all of the above areas.
5. Improves digestion
Intermittent fasting improves digestion by giving the body time to fully digest the last meal before more food is shovelled in. When we swallow, our food isn’t immediately digested. It actually takes 2-4 hours for our stomach contents to just empty into our small intestines. Then the rest of our digestive organs need time to process all the food, release digestive enzymes to break it down and finally to absorb all the needed nutrients.
It's kind of like using a funnel to fill spice jars - you can only put so much into the funnel at a time, otherwise it gets clogged and slows down. This phenomena in relation to digestion is likely due to the extended day many of us have thanks to the invention of electricity. Our ancestors would get up at sunrise and go to bed at sunset as there wasn't electricity to keep working/playing. This resulted in a lengthly sleep and corresponding fast that allowed for optimal digestion. Interesting!
**Disclaimer: As the field of Holistic Nutrition reminds us, we are all biochemically unique, which means that what works for one person might not work for another. If you are interested in the benefits of intermittent fasting for your health concerns, please contact me for a FREE consultation to discuss whether fasting is a good fit for you and your individual needs.
Can anyone try fasting?
There are some people who should not practice fasting including:
- Those under 18 years of age
- Those who are underweight or who are looking to gain weight
- Those with low blood sugar
- Those with eating disorders or who are at risk of an eating disorder
- Pregnant / nursing women
I have done intermittent fasting on and off a few times now and the biggest benefit I find for myself is improved digestion. The "stuffed" feeling disappears and my bowel movements are better because my body actually has the time to fully digest everything!
Of the different types of fasting I prefer the time-restricted version, specifically "16/8" where you fast for 16 hours and eat within an 8-hour window. I find this type of intermittent fasting works best for my particular lifestyle, my hunger and my energy levels. I also find it the most logical as it follows our natural daily schedule versus the other forms of fasting which are quite extreme and disruptive compared to our usual norms.
You don't need to fast or diet to stabilize your blood sugar or lose weight. You just need to eat better in general and move your body more!
As for my improved digestion, fasting showed me that we don't give our bodies the time they need to fully digest the food we eat. Eating dinner a little earlier is a simple way to increase your natural fasting window without committing to a full fasting regime!