Dr Michael Mosley presented another BBC Horizon on Monday night (Eat, Fast And Live Longer), this time demonstrating the health benefits of calorie restriction (CR). It works a bit like wealth. When you have money you don’t darn socks, you just buy new ones. When times are hard you darn socks. Fasting forces the body to switch from cell replacement mode to cell repair mode and, by doing so, protects against some of the big modern killers such as heart disease and certain cancers. It also lowers the risk of diabetes.
There are various ways of tackling fasting. One is to follow a daily regime in which you eat 0.75 calories per hour for each kilo of your healthy target weight. So if your healthy target weight is 50 kg you should eat 50 x 0.75 x 24 calories a day. That comes to just 900 calories, which is incredibly harsh.
Dr Mosley’s preferred method is to eat normally five days a week but consume only 600 calories (500 for women) on two days. Also very tough.
In fact, this was the same Michael Mosley who recently made a Horizon programme advocating high-intensity training (HIT). Michael assured us he was so impressed by the health benefits of HIT that he would be continuing HIT for ever. Well, that didn’t last long. And I don’t think his fasting will, either.
I am a vegan and my calorie intake is already fairly low. I hesitate to go much lower. In any event, as I explained in my book Help Yourself To Live Longer, protein restriction may be more important than calorie restriction.
My personal view is that it wouldn’t be possible for me to lead the sort of life I enjoy while fasting. I like plenty of physical activity (which doesn’t entitle you to more calories under CR).
If you’d like to know other ways of increasing your chance of living a long and healthy life you can buy Help Yourself To Live Longer from Amazon and all the usual outlets.
I did try eating 500 calories for one day only.That night I had a dream in which I was very irritable and when I woke up the next day I was still irritable. Breakfast fixed that. I haven’t been inclined to try again although several friends have said that they soon got over the initial assorted unpleasant side effects and insist they feel fantastic. My compromise has been to up my intake of fruit and veg as a preliminary flirtation with calorie restriction or maybe raw food diet