Intermittent fasting (IF) is a concept that you might well have come across through the media. Essentially, it involves periods of abstinence from eating. Theoretically, this could offer benefits in the way of increased energy, weight loss, and blood glucose management. Since advice differs between sources, figuring out intermittent fasting can get confusing.
Although there is an entire module dedicated to intermittent fasting, later in the Program, we’ve come up with a guide to intermittent fasting, so you can learn about its potential use, and how best to incorporate it into your lifestyle.
The science behind fasting Fasting is not actually anything new – it could be considered an ancient practice, due to its roots in many spiritual teachings. Over the course of several decades, scientists have studied the effects of fasting on the body and mind; it seems that a break from eating can support digestive function. This is because the process of digestion can be taxing on the body – especially when large and/or frequent meals are eaten. Thus, when allowed to rest, energy can be expended elsewhere – for growth, repair and general maintenance of the body.
The idea behind intermittent fasting is that you introduce extended windows of time during the day when you do not eat – usually anywhere between 12-36 hours. Whilst this may sound alarming at first, it’s actually more straightforward than you might think. For example, let’s say you eat your last meal of the day at 7:00pm. You then eat breakfast in the morning at 9:00am. A total of 14 hours has elapsed between eating, but a large proportion of this was spent sleeping. Hence, why we call the first meal of the day breakfast : because we are breaking the fast .
The proposed benefits of intermittent fasting are as follows:
Lowered blood glucose levels Over time, this is said to increase insulin sensitivity, and may be an important step in managing type 2 diabetes [1].
Increased weight loss Regulated appetite and reduced cravings are in themselves useful in terms of weight management. Additionally, when the body is in a fasted state, it will switch to burning its fat stores for energy, resulting in weight loss – something you may be aware of through following the Low Carb Program.
Improved brain function Fasting is believed to induce something called autophagy – an essential process of renewal our bodies go through. This is very important when it comes to the brain, helping to improve memory, cognitive function and mood.
Other advantages intermittent fasting may include:
Experiencing increased energy levels and less fatigue. Reduced inflammation in the body, which could help to prevent certain chronic diseases. A reported longer lifespan! There are several ways to fast intermittently; we’ve narrowed these down to three for maximum flexibility.
Bypass breakfast – brunch could well be the most important meal of the day! By now, you’re probably aware that a lot of our beliefs challenge mainstream advice. The idea that breakfast is the most important meal of the day could to an extent, be a myth. For those with type 2 diabetes, blood glucose levels tend to be higher in the morning due to something known as the dawn phenomenon, which is caused by the liver releasing glucose during the sleep [2].
For some, choosing to skip breakfast can help to avoid blood glucose highs. Eating later in the morning can help to maintain blood sugar balance. Effectively, this involves eating two, substantial meals a day instead of the usual three.
Fast once a week for up to 36 hours For some, a Saturday or Sunday is preferable, as it’s generally advisable that you take it easy during a fast. Using Saturday as an example, this would mean that from your evening meal on Friday, you would not eat again until Sunday morning. For some, this provides focus for a well-earned rest that increase productivity throughout the week.
The 5:2 principle, with an overnight fast This is a similar idea to well-publicised 5:2 diets, but instead of the proposed 500 calorie limit, we advise a virtually zero carb intake for two days a week. We also recommend allowing 12-14 hours between your evening meal and breakfast (as previously outlined). This is, therefore, a partial fast of sorts, and probably the subtlest method of fasting; it's useful if you’re trying it for the first time.
Of course, you could use a ‘rotation’ system, whereby you try all three over the course of several weeks.
There are a few notes to bear in mind:
It’s important for you to stay hydrated when fasting – especially if you try the second method; not doing so could be harmful to your health. Eating a lot of food following a fast counteracts the purpose of fasting in the first place, and so it’s best to eat nutrient-dense foods that contain healthy fats and protein to enable you to attain maximum benefit from intermittent fasting. It’s advisable to seek medical advice before making any drastic changes to your eating habits. If you decide to try intermittent fasting, you’re likely to find it can bring many, welcomed effects to compliment your low carb lifestyle.
References Halberg, N. et al. (2005). Effect of intermittent fasting and refeeding on insulin action in healthy men. Journal of Applied Physiology , 99(6), pp2128-36. Available at: http://www.ncbi.nlm.nih.gov/pubmed/16051710 Porcellati, F. et al. (2013). Thirty Years of Research on the Dawn Phenomenon: Lessons to Optimize Blood Glucose Control in Diabetes. Diabetes Care, 36(12), pp3860-62. Available at: http://care.diabetesjournals.org/content/36/12/3860 
