Intermittent fasting has become a popular health trend in recent years. Not only is it being touted as an aid in weight loss and improved metabolic health, it may also promote a range of other health benefits including improved heart and brain health, a lower risk of diabetes, and even a longer life!
Author and neuroscientist, Mark Mattson PhD, highlighted that as agriculture has been around for only 10,000 years or so, “we are genetically geared to function well in a food-deprived state”.
There are several ways to undertake fasting. Whether it be restricting your eating to a 6 to 12-hour window per day, or eating normally a few days a week, then radically switch to calorie restriction for 2 or 3 days, both have been shown to support weight loss and metabolic health. However not all may work best for you. It is a matter of trying a few different ways and seeing what works.
The 16/8 method
This method means fasting every day for 14-16 hours, which restricts your daily eating to 8-10 hours. You can have two, three or more meals in that window. This method needn’t seem daunting. It can be as simple as not eating anything after an early dinner, and then skipping breakfast. For those who find that they get hungry in the morning and need breakfast to focus, then this form of fasting may not agree with them. You can drink water, coffee and zero calorie drinks during the fast which may help reduce those hunger pangs. It is important to eat healthy foods within your window of eating time for the fasting to work. Women are advised to only fast for 14-16 hours.
The 5:2 Diet
So, this method revolves around eating normally for 5 days of the week and then restricting calories to 500-600 per day for two days. For example, you may eat normally every day of the week except for Mondays and Thursdays. You can choose the two days that you want to fast which best suits your weekly schedule. On the fasting days it is recommended that women’s calorie intake is 500 per day.
Eat. Stop. Eat. Diet
This diet involves fasting for 24 hours once or twice a week. For example, fasting from dinner one day, to dinner the next amounts to a full 24-hour fasting period. Water, coffee and zero calorie drinks are allowed, but no solid foods while fasting. Most people will be doing this diet to lose weight and it is important to remember that on non-fasting days you need to eat as you normally would, as if you were not fasting at all. The possible downside of this particular diet is that many people may find it hard to fast for 24 hours. If this is the case, start with 14-16 hours and build up your fasting hours slowly.
Each diet is different and one may fit our lifestyle better than the other. As always, we need to critically assess what will work best for us as an individual. Anyone with a health condition needs to undertake these changes in consultation with their health-care practitioner.
The evidence that intermittent fasting benefits the wellbeing of overweight people is already very strong, but what about its potential impact on disease? The great news is there are plenty of promising human trials emerging and dozens more underway, so watch this space!