Seeing as it is hot and most of us are experiencing a reduced appetite, I thought it a good time to write about fasting. Perhaps this heatwave could provide a good time to give it a try, given most of us are halfway there already!
Fasting has recieved plenty of positive press over the last few years, with a big chunk of mainstream awareness being brought with the 5:2 diet.
Fasting is great for purely cutting out the calories from a meal or two – and hence reducing your intake for the day – and the benefits include reduced body weight and fat.
There are plenty more benefits to fasting than this though; even people who are not trying to lose weight see improvements through fasting. This said, most of the researched benefits are currently linked to a reduction in caloric intake rather than something which is happening because of the actual fast. This means that studies relating to fasting always seem to include a weight loss component – the benefits of fasting without weight loss haven’t been studied much at this point, although there are plenty of people who have experienced improvements with fasting which are not related to weight loss.
The other thing to say about fasting is that its probably not the right thing to do right from the get-go. If your diet isn’t as good as it could be, then jumping straight on board with fasting probably isn’t the best choice – you’ll be much better served by simply improving your diet and settling your body into its new choices, before starting to include fasting in your life.
The main documented benefits of fasting relate to improved blood sugar control, improved digestion, reduced gut-related symptoms, potentially improved ‘clearing out’ effect of old cells, improved mood (there is an interesting link with depression), more constant energy levels, reduced food cravings, a sense of ‘liberation’ from thinking about food all day.
So, if you’re ready to give fasting a go, how do you do it?
This sounds like a silly question, and the answer is of course exactly what you think it is – ‘just don’t eat’. But these things like to be complicated, and there is a bit more to it than that.
Most of the benefits seem to arrive and peak somewhere around 12-18 hours without food, and when we align that with what we know about circadian rhythms and feeding our bodies in line with when we want them to be active and when we want them to sleep, we find an optimal pattern of finishing eating as early as possible (in fact, meals after 2pm have a progressively bigger effect on waking blood sugar levels the next morning) and waiting at least 12 hours over night until you eat again. Really, this should be called Time Restricted Feeding rather than fasting – but since it is a period of not eating, I tend to refer to it all under the umbrella of fasting.
For other people, this pattern difficult to fit in as they can’t eat dinner so early and perhaps aren’t quite ready to only eat breakfast and lunch. If they still manage at least 12 hours between dinner and breakfast, it’ll still get the job done, its just not quite as optimal as the approach I’ve described above.
As well as an overnight fast, it is a good idea to stop snacking during the day too, so in a 24 hour period, you’ll go at least 12 hour overnight without food and then another two 4-5 hours between each meal.
There are many advocates of doing longer (correctly termed) fasts too. 16-18 hour probably counts as a true fast, and many people enjoy a 24 hour fast once every week or two. Some people fast up to 6 days once or twice a year, and a few even longer – although I’d suggest a lot more knowledge and understanding before you give these a try.
An important and often forgotten aspect of fasting – especially the much longer, true, fasts – is what you should eat afterwards. Clearly, your body will be fairly low on nutrients after a fast since it has been relying on its stores; so it is very important to make sure you eat plenty of nutrient dense foods rather than breaking your fast with donuts. A lot of the magic of an extended period of reduced intake comes afterwards.