This week I thought it might be interesting to explore the very hotly debated topic of Intermittent Fasting. Have you tried it? How did you feel? I know many that swear by it for weight loss, energy and generally feeling good and others who feel best on 3 square meals per day!
As the topic is quite heavily laced in research and science, I’ve popped in a few quotes and opinions from Nutritional Therapist Grace Kingswell along the way.
The first thing I want to say is that it’s so important, as with anything, to really tune into how you’re feeling rather than leave things up to the effects of caffeine, painkillers, sugar highs etc. What I mean is, all too often these days we go about our lives not really listening to our bodies, just carrying on, pushing through with another cup of tea or an energy boost from a mid-afternoon snack. What I love about fasting is that it really gives you the opportunity to tune into your own body’s hunger signals and many other cues that spell out how you’re feeling.
Our hunter-gatherer ancestors had to work a lot harder for their meals, and as such they would have gone for much longer periods without food than we ever do. As such, our bodies are designed to switch from burning carbs for fuel to burning stored fat for fuel. Ketosis works on the same principle - it’s just another way of creating energy and often allows us to tap into those valuable stored fat reserves, liberating energy and supporting brain health with the release of beneficial ketones.
What is Intermittent Fasting?
It sounds really simple doesn’t it? Going for a period of time without eating. However, there’s a bit more to consider if you want to really tap into the reported benefits.
It takes 10 hours for the body to use up all its available energy from food. When we go past these 10 hours, the body then mobilises stored energy in the form of fat to keep you going too, but is also when the other processes that have been associated with fasting come into play: detoxification and cellular repair, turning white fat into brown fat etc.
So this begs the question, can you really be in a fasted state and drink a bulletproof coffee, for example? The reason lots of people ‘get away’ with a bullet proof coffee on a fast is because adding fat to your coffee technically doesn't raise blood sugar in the same way that milk does, as there is no sugar. MCT oil also bypasses standard digestion, due to the size of the molecule, and goes straight to the liver where it can be turned into ketones and used as fuel in a ketogenic state. Nuances aside, having a bulletproof coffee on an intermittent fast isn’t going to take you massively out of a fasted state, so you’ll still reap the benefits of the fast.
The Different Types of Fasting
By far the most popular type of fast is the 16:8, where you fast for 16 hours and feed for 8. This is certainly the most accessible form of fasting as really all it’s doing is reducing your eating window but allowing you to tap into the fasting benefits by extending your period without food. It’s also easy to work into your daily routine.
Calorie restricted fasting is simply the reduction of calories throughout the day, which actually still mimics the fasted state. The most popular example of this is the 5:2 diet, where you eat normally for 5 days of the week and then dramatically reduce calorie intake for 2 days, say 500-600 calories. It shocks the body into burning stored fat for fuel as the calories coming in aren’t enough on their own to power metabolism.
p.s. Our Keto Vegan Bagels are the perfect post-fast snack: low in sugar, keto and high in beneficial fibre!
The Benefits of Intermittent Fasting
A seminal study in the 1930s showed that restricting the calorie intake of rodents led to a longer lifespan compared to those that were able to eat freely. We’ve never before had such an abundance of food as we do now, and we are constantly grazing and snacking all day long as well as taking in a glut of calories and nutrients from our three main meals. Many argue that intermittent fasting, or sporadic periods of longer fasting, is actually just a regression to the way we used to eat - foraging, hunting, filling up, and then going a while with less before the next feed.
Here’s a quick round up of a few of the scientifically backed benefits of fasting:
- Increased human growth factor hormone
- Improved insulin sensitivity which facilitates fat burning
- Weight loss
- Cellular clean up (destruction of damaged cells) or autophagy.
- Reducing inflammation
The Drawbacks of Intermittent Fasting
It was important to me in writing this post that I presented both sides of the story, as like I said to begin with, ultimately healthy living comes down to what makes you feel great, not what everyone else is doing.
“I always question whether fasting is actually more beneficial for men over women, and I prefer my female nutritional therapy clients to not skip meals. The reason for this is that our hormones require the thyroid hormone T3 to be working adequately. When we don’t eat for long periods, such as with an intermittent fast, our bodies are very clever and they slow down our thyroid and our metabolism to conserve nutrients. The problem with this is that when we have lower T3 production our sex hormones can get out of balance very quickly: painful periods, PMS, mood swings, low libido etc.
So, one of the simplest things I can do as a nutritional therapist to help balance hormones is make sure that my clients are nourishing their bodies adequately, and for some people with severe blood sugar issues, insulin resistance, PCOS etc this might even mean eating a balanced meal or snack every 2-3 hours!
One thing I would say, however, is that if you are going to fast then in my opinion it’s much better to fast in the evening rather than the morning. Societally speaking, skipping breakfast makes sense, it’s easier and less unsociable. But as humans we have evolved to live in tune with the sun and oftentimes in the 21st Century we are having our main meal at night time when the sun has gone down. This is metabolically very confusing for our bodies and skewes our melatonin production and sleep cycles. Breakfast is an important meal, I really believe that no one should skip it!” - Grace Kingswell D.N.Med
Intermittent fasting is a complex topic, and actually I could delve further into it than I have, but I hope this blog post has presented you with a balanced view and some things to think about!
Have you tried intermittent fasting? Let us know in the comments below!