Back in the days of hunter-gatherers, the human body evolved to be able to function without food for extended periods of time. Contrary to the ‘3 hearty meals a day’ narrative that has been instilled into us, it is believed that fasting occasionally can potentially be a more natural and healthy eating behaviour than consuming 3-4 meals per day.
Intermittent fasting is best described as an eating pattern that cycles between periods of fasting and periods of eating. Rather than specifying what you should be eating, intermittent fasting methods regulate when you should be eating. During these fasting periods, you are still encouraged to drink water and herbal teas, to stay hydrated.
Done safely and correctly, intermittent fasting can have powerful and beneficial effects on your body and your brain, including reduced fatigue and weight loss (as long as you don’t overcompensate by binging during eating periods). That said, it is only beneficial to us when done safely and with a good understanding of your own body’s needs. There is no one-size-fits-all solution when it comes to nutrition and you shouldn’t launch into fasting without seeking professional advice first; intermittent fasting can be tricky and should be done with care and consideration!
In this blog I am going to outline some of the more popular methods of fasting, as well as briefly explaining how and why it works.
Popular Intermittent Fasting methods
There is no one correct way to fast. As I mentioned previously, everyone has different individual needs and what will work for one may not work for another.
• The 16/8 method (a.k.a Leangains Protocol)
This is probably the most popular and accessible way of intermittent fasting. The 16/8 method involves eating during an 8-hour window and fasting for the remaining 16 hours of the day. For instance, you may decide to skip breakfast and then eat between the hours of 12-8. You can move this window depending on your personal preference/schedule.
If you are just getting started, try a 12/12 ratio. This is most easily achieved by making sure you don’t snack after your evening meal, which may be at 7 o’clock. This way, you are resting your digestive system until 7 am the next morning, giving it an opportunity to do some repair.
The Eat Stop Eat method is an approach to intermittent fasting characterised by 1 or 2 non–consecutive days of fasting per week – during these fasting periods you are still encouraged to drink water and herbal teas to stay hydrated. For the remaining 5 or 6 days of the week you are free to eat as you wish, however it is recommended that you still eat sensibly and follow a healthy lifestyle to reap the benefits of this food plan.
• The 5:2 diet
The 5:2 diet is a more manageable version of the Eat-Stop-Eat method. Rather than cutting out food completely in the fasting periods, you consume only 600-700 calories on two chosen days of the week, whilst eating normally on the other five. This drastic reduction in your intake still produces the same effects that fasting would, but in a healthier, safer way, helping to balance blood sugar levels. A really good lead in to this is Michael Mosely’s book, ‘The 5:2 diet’.
The Science Behind Intermittent Fasting
Intermittent fasting aims to create a healthier terrain at a cellular and hormonal level. Obviously through restricting food intake, your calorie intake is naturally reduced and therefore may support weight loss. Here, I will briefly outline how and why intermittent fasting works the way it does:
• Lowers Insulin Levels
Insulin is produced in our bodies in response to eating. Once released, insulin causes the body to store energy as fat. Therefore, the more you eat the more insulin is made and the more fat you store. When you fast, your insulin levels are lowered and the fat-storing process is reversed, enabling your body to use your fat stores as a source of energy instead of food!
• Ghrelin and Leptin
Ghrelin and leptin are two of the main hormones involved with hunger and satiety.
Ghrelin is the hormone which is released to tell you when you’re hungry. Some research has suggested that intermittent fasting slows the release of ghrelin, as your body’s routine readjusts.
Leptin is the satiety hormone; it tells you when you’re full and reduces your cravings for food. Intermittent fasting is believed to increase the release of leptin in the body and therefore reduces your desire to eat.
With more leptin and less ghrelin, you will feel fuller for longer and hungry less often, meaning your hormones are working in a more balanced way.
Precautions & Side Effects of Intermittent Fasting
While there are many benefits to intermittent fasting, it can be incredibly detrimental when done without proper guidance and understanding. If you’re underweight, have a history of eating disorders, or have a pre-existing medical condition (such as diabetes, low blood pressure, pregnancy etc.), you should not fast without consulting with a health professional first. Everyone has individual requirements when it comes to nutrition and fasting may not be your best option!
Hunger is the main side effect of intermittent fasting. As you’re getting started you may feel a little weaker or fatigued, and your brain might not perform as well as you’re used to. This will pass, it is only that your body can take some time to adapt to an adjusted meal schedule. Once your body has adapted to this process, many people report feeling full of energy, a healthier glow, greater clarity and focus and increased positivity as a result of fasting.
Intermittent fasting has an outstanding safety profile and if you’re healthy and well-nourished overall, you are likely to reap the benefits of this lifestyle.
Intermittent Fasting Advice from a Nutritional Therapist
After the busy Christmas period, it seemed fitting to give my body a rest with a 5-day juice and soup regime. I have more or less cut my calories in half. This is a more advanced type of fasting than the ones detailed above, including 4 juices throughout the day, a home-made vegetable soup in the evening and water and herbal teas in-between (not for the faint-hearted, but I’ve done it a number of times before and my body as adapted!)
I am only on day two and already feel energised but calm and comfortable at the same time. If this is something you might be interested in, then I advise you to get in touch with me for a no-obligation, free discovery call. In this chat, we can discuss your current food plan, your goals and how best to get you there using fasting! I look forward to hearing from you.