There are a number of different ways to do intermittent fasting. One of the most popular of which is the 5:2 diet, also known as the Fast Diet. Since writing The Blood Sugar Diet, we have found that the best way to do the 5:2 diet is to cut down to 800 calories on two days a week, whilst eating a healthy Mediterranean-style diet on the other days too. This has since been shown to be one of the most effective ways of losing weight and keeping it off, in addition to reducing diabetes as well as risk of certain cancers, inflammation, dementia and heart disease.
Another way of practicing intermittent fasting is to restrict the number of hours during the day in which eat, known as the 16:8 diet. It’s been popularised by the Wolverine actor, Hugh Jackman, who credits it with helping him develop his impressive physique. To do a 16:8 diet eat all your calories in an 8 hour window, then fast for 16 hours overnight. Some of the benefit comes from having a longer period without food, but also from the fact that people were eating their evening meal earlier. It is generally better to eat your calories earlier in the day rather than later. From about 8pm onwards your body is preparing you for sleep. Your blood sugar and fat levels will naturally be starting to rise because your body knows it needs to keep you going until morning. If you now eat a big meal, that will make those sugar and fat levels in your blood stay higher for longer.
I recently did an experiment on myself where I ate a hearty meal for breakfast and measured my blood sugar and fat levels. These rose and then fell back to normal within a couple of hours as I got on with a busy day. I then fasted for the rest of the day and then ate exactly the same meal at around 8.30pm. This time my sugar and fat levels rose and stayed up for more than four hours after the meal.
There is one species of bacteria in our gut that flourishes when we fast – Akkermansia. This lives on the mucous that lines our guts, keeping the lining of the guts in good shape and reducing inflammation.
So, there are various ways to fast. But essentially it comes down to what you find easiest and most effective to do.
Before embarking on a fasting diet, it is worth checking if it is suitable for you. The following two websites detail different fasting programs and their suitability: