Many diet trends have origins in legitimate science, but once they hit the mainstream, benefits can become greatly exaggerated, risks are ignored and science quickly succumbs to marketing.
And, in a day when facts and fads can be easily blurred, it is becoming increasingly hard to know what to believe.
It helps to remain healthily sceptical about, well, everything these days, but mainly things that are going to directly affect your health.
Enter intermittent fasting.
For those who don’t know, intermittent fasting is exactly what the name suggests. There are a few variations, but the most popular one at the time of writing is ‘5:2.’ That’s five days of normal eating, where you can eat whatever you like (yep, even that family-sized pizza). Then, for two days, you reduce your calorie intake to 500 calories for women and 600 calories for men.
An important note is that the 5:2 diet is not designed for weight loss, rather to “send you down a path towards a longer, healthier life.” Weight loss is simply a happy side effect.
Until recently much of the research that supported fasting was done on animals. These studies found a link against obesity, type 2 diabetes and cardiovascular disease, along with several other things, most notably reduced metabolic risk factors associated with cancer.
But we’re not animals, so you should take all of that with a grain of salt (0 calories in that, if you’re wondering).
Thankfully, a new study published in the Journal of the American Medical Association, by nutrition professor, Krista Varady, was done on humans. It compared people who followed a traditional restricted-calorie diet against those who were told to fast every other day for a year. A control group who ate normally was also included.
At the end of the year, people in the standard diet group and the fasting group lost similar amounts of weight, compared with those who didn’t do anything. They also came away with similar results in terms of heart rate and blood pressure.
So, in a nutshell, the study found that fasting works roughly as well for weight loss as traditional dieting does. It didn’t provide any conclusive findings on the other supposed health benefits of fasting though and despite several references on the web to a ‘growing body of research,’ until you see some cold, hard, references to in-depth studies such as Varady’s, it’s best to remain sceptical.
In Michael Mosley’s documentary, ‘Eat, Fast & Live Longer’, he found the 5:2 diet had staggering results in terms of his general health and reducing his risk of certain cancers, but he also stressed that while it worked for him, that is no guarantee it will work for others, and anyone thinking about trying it should consult a doctor first.
So, in terms of weight loss at least, fasting isn’t just a fad. It has been proven to work as well as any other diet.
As for the other health benefits? The jury is still out.
What is certain, is that fasting isn’t for everybody, but if your main aim is weight loss and you’ve been struggling with traditional diet regimes, it might be worth a try. Just make sure you visit your doctor first.