Counter-intuitive as it may seem, no foods are off-limits, none proscribed. On the five days a week when we’re not restricting calories, we both eat freely – fish and chips, roast potatoes, biscuits, cake. The Illinois study certainly found that volunteers encouraged to eat lasagne, pizza and fries during ‘off days’ still lost weight.

One other significant benefit to Intermittent Fasting is that you don’t seem to lose muscle, which you would on a normal calorie-restricted regime. Krista herself is not sure why that is and wants to do further research.

The size of the sugar spike depends both on the food itself, and on how much of it you eat. For example, we tend to eat a lot more potatoes in one sitting than kiwi fruit. So there’s also a measure called GL, the Glycaemic Load, which: GI x grams of carbohydrate 100

When we eat food, particularly food rich in carbohydrates, our blood glucose levels rise and the pancreas, an organ below the ribs and near the left kidney, starts to churn out insulin. Glucose is the main fuel that our cells use for energy, but the body does not like having high levels of it circulating in the blood. The job of insulin, a hormone,

The villagers with Laron syndrome are normally quite short; many are less than four feet tall. The thing that is most surprising about them, however, is that, like the Laron mice, they simply don’t seem to develop common diseases like diabetes and cancer. In fact, Valter says that, though they have been studied for many years, there is not a single

Regular walkers have brains that in MRI scans look, on average, two years younger than the brains of those who are sedentary.

11

felt a certain trepidation as I realised that for the next four days I would be drinking nothing but water, sugarless black tea and coffee, and one measly cup of low-calorie soup a day.

While there are few known risks involved in fasting for less than 24 hours, the same is not true of prolonged fasts.