OK the title is a bit of a come-on but this week’s BBC2 investigation into the benefits of fasting by the Horizon team, actually entitled “Eat, fast and live longer “, did become very enthusiastic towards the end. Understandably. It wouldn’t be over-egging it too much to say that if you were looking for a single thing that could slash your risk of chronic disease, reverse the obesity crisis and keep you healthy right up until the final popping of the clogs, then scheduled fasting is a plausible candidate.
Of course at one level it is bleedin’ obvious that eating less will make you lose weight. But why exactly should being overweight be linked with a dramatically increased risk of diabetes, cancer, heart disease and possibly Alzheimer’s? We all know it is but why? This is what made the program so fascinating. It told a new and radical story that connected all those strands and suggested how you could get all the benefits without too much pain.
Briefly the plot goes like this. Ageing researchers have known for over 70 years the if you keep virtually any lab animal on about 3/4 of their normal diet – around 1300 to 1500 calories for a human – they will not only live up to 50% longer but be glossy, healthy and energetic right to the end. The reason, modern genetics tells us, is that calorie restriction, or CR as its known, dials down the action of a gene that controls how much of a hormone called IGF-1 (insulin growth factor 1) you produce, which is needed for growth and is closely related to insulin.
The cancer-free dwarves
Star witnesses for this claim are some dwarves who live in a remote part of Ecuador and never get diabetes or cancer. A rare mutation has given them unnaturally low levels of insulin and the growth hormone – hence the dwarf bit – which means that even though they eat pretty unhealthy food and have high levels of blood sugar, they stay remarkably healthy. Intriguingly this puts insulin in the frame as a prime suspect for our obesity and chronic diseases epidemics.
So the challenge Horizon’s reporter was how to get the CR benefits without the daily grind of feeling cold and hungry? And there was an answer to that too. You don’t have to fast all the time just maybe have no more than about 600 calories a couple of times a week. The reporter did that for five weeks and lost 20 pounds and had half the IGF-1 level he did when he started.
Now I think that is a pretty intriguing story, but then I would because it is almost exactly the one Patrick and I told in our book ’10 Secrets of Healthy Ageing’ and in the Daily Mail. Now I don’t say that to trumpet the fact that I was on to all this a year ago (well, only a bit) but to point up what an absurdly tiny band of researchers are looking into this.
Does it work for everyone?
There were four key researchers interviewed and I have written about three of them. The fact the pool is so small is appalling because there should be dozens of labs following up on this major rethink of the biggest health problem facing us. There is no shortage of possible angles such as does the kind of food you eat while you are cutting back matter or is it only the calorie total that matters? Does it work for everyone? Could it be dangerous? What are the long-term effects?
The official line is that we need around 2000 calories a day, low-fat is good and fasting is far too much like a fad. And of course there is another major and probably fatal objection to some form of fasting – it is very difficult to make money out of encouraging people to eat less. Certainly nothing like the ten billion predicted for the newly licensed diet pills that come with a raft of possible side effects that include birth defects and heart problems.
Shortly I’m going to post an extract from the book that tells some of this story as well as one that gives a detailed account of an occasional fasting schedule you might like to try out.