THE RESEARCH
Want to feel younger, lose weight, support your heart health and reduce your risks of developing type 2 diabetes – all without changing what you eat? Of course you do. We all do. While it sounds like an impossible dream, it’s not. The key is changing when you eat. You might have heard about fasting diets before – also known as intermittent fasting, or time-restricted eating – but I have developed a version, which I’ve used with hundreds of clients in my nutritional practice, that I think is the easiest of the lot. You simply eat your existing diet within only ten hours of the day. This enables your body to have a long overnight fast of 14 hours, most of which you’ll be sleeping through anyway. These 14 hours without food are when your body turns its attention to burning fat and remodelling almost every organ to help you stay young and healthy for longer.
There are several good reasons why the latest and most credible thinking around health and weight loss centres around intermittent fasting or time-restricted eating and, while I don’t want to blind you with science, I do think that having an understanding of why a diet can succeed is more likely to make you want to stick to it, so here’s a quick rundown of how we’ve got to this point.
Between 2012 and 2015, a huge amount of research was done on mice. Researchers divvied them up into groups and fed them all exactly the same daily calorie counts of various chow concoctions, high in fat and sugar. The only difference between the groups was the timing of when the mice could eat. The mice who could only eat their food in eight- and nine-hour blocks of time lost weight and had better insulin and cholesterol measures, whereas the mice who ate whenever they wanted became obese and diabetic.
Then it was time to see if the theory applied to humans. So researchers asked a small group of overweight and obese people to eat in a 10-hour time slot each day. The results? On average they lost 3.2kg (about 7lb) over 16 weeks – all without counting a single calorie or changing their diets.
More recent research has shown that in a small group of people with metabolic syndrome – a combination of obesity, type 2 diabetes and heart disease – after three months of eating only in a 10-hour window, they also lost an average of 7lb, lost four per cent of their waist measurement, reduced their blood pressure, improved their cholesterol readings and the markers related to diabetes, too.
And while it was previously thought that the longer you fasted the better the results, in fact other studies seem to show that fasting for 14 hours not only gives better results than fasting for 16 or even 18 hours, but is more sustainable in the long term.
The reason why we think fasting works at all is because when we go more than 12 hours without food, a ‘metabolic switch’ gets turned on in the body, helping us thrive and survive. The great news is that it’s thought that the first couple of hours after these 12 hours may be the most useful ones to our body, hence eating in a 10-hour time slot and fasting for 14 hours overnight is a practical way to get benefits without hardship.