Posted on 07/12/2019
First released back in 2013, this book focuses on the health benefits of intermittent fasting (IF). It offers a practical guide to implementing IF into your lifestyle, built around the idea of eating normally for 5 days a week, but limiting your calorie intake to only 500-600 calories per day on the other 2 days (i.e. the 5:2 model).
Motivated as much by his own personal need to take action to control his weight, blood sugar and familial risk of developing diabetes as he was by the broader question of how we combat the obesity and diabetes epidemics that plague people all over the world, Michael explores the science behind how IF helps to regulate our body’s metabolic functioning, and shares the dramatic improvements in weight loss and blood sugar control that he experienced as a result of intermittent fasting.
Here are the key “take home” messages that we have pulled from the book:
1. Reputable scientific studies suggest that intermittent fasting (IF) promotes health and longevity because it stimulates the natural “repair and maintenance” processes that take place within the cells of our body.
There are a number of mechanisms by which this happens: IF reduces the levels of an insulin like growth factor called IGF-1 circulating in your body (which has been implicated in accelerated ageing and increased cellular turnover/cancers), it reduces oxidative damage and inflammation within the body, it helps to optimise energy metabolism, it switches on some of the body’s “repair” genes, it helps to keep your immune system functioning properly, and it bolsters cellular protection.
Thus, IF has the potential to delay ageing, and to help prevent or treat many kinds of disease including cancer, high blood pressure, type 2 diabetes, asthma, obesity and others.
2. Intermittent fasting helps people lose weight in a safe and sustainable way.
Importantly, this weight loss stems from reductions in body fat levels (which is exactly what you want) as opposed to the loss of lean muscle tissue (which is exactly what you don’t want).
Just as importantly, Michael suggests that this weight loss is not merely the result of ingesting fewer overall calories as a result of the reduced caloric intake on the two fasting days, but by improving the body’s sensitivity to the energy storage hormone insulin.
Put simply, insulin inhibits your body’s ability to burn fat for energy, but because IF can help to improve insulin sensitivity within the body there tends to be less of it floating around in the bloodstream all the time, thus making it easier for your body to burn stored body fat for energy and helping to ensure that the weight loss you experience is due to fat loss rather than muscle loss.
3. Intermittent fasting can dramatically lower blood glucose levels.
Elevated blood glucose levels is one of the key features of type 2 diabetes, and this “sugary” blood is quite damaging to the cells of your body tissues, and in particular to your blood vessels. The consequences of this damage include an increased propensity for stroke, heart attack, kidney disease, visual loss, cognitive decline, and many other serious health disorders.
Michael describes his own improvements in blood glucose levels as “spectacular”, and relates how his doctor – who had been preparing to put Michael on medication to try and control his blood sugar levels – was astonished at the dramatic improvement. Needless to say, the medication wasn’t necessary.
There are many other important messages contained within this book, and it also offers practical ideas about meals that can be used on those days when one is fasting, but perhaps its greatest strength is that it has shown that not only is there good science behind the concept of intermittent fasting, but that it is a safe and sustainable way that most people can use to make to make significant improvements in their health and longevity. We happily recommend the book to everybody.