Should we all be following strict rules around fasting?
The potential benefits of fasting for the body have been talked about for a long time, but the idea that restricting your eating to a certain time window is good for health, seems to be building momentum so what does the science say?
Fasting allows the digestive system a chance to rest and in this time, the daily ‘spring clean’ can take place. Without the signals to release hormones for digestion, order can be restored. Forgive the lack of super sciencey terms here but it’s been a long week and it’s half term tomorrow!
Our bodies natural circadian rhythm is our inbuilt clock that tells us when to wake up, when to eat and when to fall asleep. Time restricted feeding goes in line with us fasting overnight as we sleep, with this fast then being broken by the first meal of the day, which has become known as break- fast.
What does the research say about fasting?
Research has focused on the eating window of 10am and 6pm – in other words 8 hours in which you are allowed to eat and 16 hours in which you must fast, hence the term 16:8. In small studies, sticking to this regime does lead to weight losses of an average 3kg and reductions in blood pressure. The most recent study which led to my podcast interview with The Daily Mail, showed decreases in body fat percentage, waist circumference, visceral fat (which is the fat that sits round our organs) and blood pressure, in those who had diagnosed metabolic syndrome. The effects were seen as directly related to dietary changes as they were all already on medication.
A number of things (another great technical term there) seem to happen when we restrict eating in the evening. Levels of hunger hormones decrease so we feel less hungry and our cells become more sensitive to insulin which allows glucose (sugar) to reach our cells efficiently. We can see from research into shift workers, that our ability to metabolise food changes; our glucose tolerance and insulin sensitivity decrease throughout the day, and are at their lowest in the evening. Shift workers have an increased risk of diabetes, obesity and heart disease.
Clearly, eating doughnuts and Marsbars between 10 and 6pm is not what these study participants did, and there is a correlation with a reduction in calories and time-restricted feeding. However, more health benefits do seem to be emerging that are irrespective of weight, such as blood pressure and blood fat reductions.
So, is fasting right for you?
If we address our eating habits generally, and consider how we are fuelling our day, we might find we naturally improve the number hours in which we are in a fasted state. If we are prone to late night picking, because our brains simply can’t remember eating lunch and breakfast was also a bit of a none event, then this is something to work on.
If we eat late at night because we simply don’t have time to have our dinner any earlier, then consider re-distributing the calories so that our breakfast and lunch are bigger than dinner. For workplace health this can make more sense because we need more fuel for spreadsheets and client meetings, than we do for Love Island.
And whilst I maintain breakfast is important it doesn’t have to be the minute you get up, so this will also contribute to the number of hours your body is fasted for.
If you like the idea of being really regimented and you think this will have a positive influence on your eating habits, not a negative one then why not give it a try. It’s really important to stress though that the quality of your diet, how much you sleep, how active you are and how you manage your stress are all key components to healthy living and of far more value then clock watching as you put food in your mouth…