The man paced about in his cave. It was twilight, and the darkening light in the cave made it difficult to see the expressions on the face of his spouse and three children. But he was sure that they were worried. Outside, the storm raged on. Rivulets of water seeped into the cave. The cacophony of thunder was broken only by the roar of a wild beast in the thick forest outside. He had only enough food stores to last for a day, and the storm was sure to rage for at least a week more. Not to mention the passing horde of the dinosaurs, for this story is set in a time that is long, long ago. And after his limited food stores ran out, his family would starve – for a week or so, that is. That means, till he managed to hunt, forage and gather food for them again.
What our man probably did not know is that during those pre-historic times, the human body had found a biological way to survive these periods of starvation. Indeed, in those days, life was a period of starvation, punctuated by short bursts of food intake.
During these bursts of nutrient consumption, the body would store glucose in the liver as a substance called glycogen. The body would store the fat too. Excess nutrients would be used to generate protein for strength and the body would also switch on the anti-ageing genes. And what would happen during starvation? The body would first burn glycogen for energy, and then the fat stores. Next, the body would start burning up the bad proteins and switching off the bad genes responsible for ageing, or even cancer. In an article published in the prestigious New England Journal of Medicine recently, authors argue that this duet of fasting and food intake (not feasting!) would switch off and then switch on the body's metabolism to bring about health benefits.
This might have given an evolutionary advantage to humans. Moreover, the authors suggest that we can still switch on this evolutionary benefit by the well-known fad diet called "Intermittent Fasting" or "I.F.", which is the title of the editorial, and our cover story. A simple definition of intermittent fasting is that of eating at fixed times and allowing prolonged periods of fasting in between. For example, in a 5:2 fast, people would eat normally for 5 days a week, and fast on the other two days. Another variation is to restrict food intake to 8 hours of the day and devote the other 16 hours to fasting.
Unlike pre-historic times, today's life is a celebration of food intake, punctuated by very brief periods of fasting. But by a return to our ancient ways of fasting, could we manage to improve obesity, Diabetes, heart disease, cancer and even dementia? The thought is fascinating, as researchers are currently unravelling the theory that intermittent fasting works in ways that go beyond simple calorie restriction.
So should we "fast unto health"? Clearly, this fad is not for everyone. People with Diabetes on certain medications should not do intermittent fasting, as they can develop low blood sugar level or even an adverse form of ketosis. But some people would benefit from this fad diet, as you will find out from the cover story. For the final word, check with your doctor. And "FAD", my dear reader, could also stand for "food against Diabetes" or "fasting against Diabetes"! Happy reading!
Dr Unnikrishnan AG