Fasting might be making a splash in the news, but in fact it’s nothing new – people have been fasting, in some form or another, for hundreds of years throughout human history. Recently however, the 5:2 diet, and variations upon it, has enjoyed a massive boost in attention – and they are potentially set to become the fad diet of the year. Hailed as the next big health saviour, the 5:2 diet has been described as a panacea against degenerative diseases like Alzheimer’s, cancer, and of course, a short cut to rapid and easy weight loss. Unlike most fad diets, the 5:2 diet does have a foundation in scientific evidence – but just how effective is the diet, and is it right for everyone?
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The science behind the headlines
The 5:2 diet, also known as intermittent fasting (IF), or alternate day fasting (ADF) exploded onto the international health consciousness, following a BBC documentary into the age-old practice of fasting. When the presenter, Michael Mosely, reported significant weight reduction through this approach to eating, it has since caught on like wildfire as a fast and fool-proof path to weight loss. So how does it work?
A short cut to weight loss?
The sensationalist depiction of intermittent fasting is often quite extreme, based around ‘fasting and feasting’, with periods of extreme starvation followed up by an “all you can eat” binge. Going by tabloid stories – two days of fasting are merely an invitation to consume as much as physically possible on other days. But while it might be psychologically appealing to choose a diet that gives you free license to eat whatever – and however much – you like, the reality of the 5:2 diet is far more moderate.
Unlike conventional diet plans which advocate a small reduction in calories every day, fast days are normally based around two days of significantly low calorie restriction – between 500-600 calories for women and men respectively, or in some cases, nothing at all. Non-fast days by contrast are based around a moderate “normal” diet, without any deliberate restrictions. While the odd indulgence might be included within this, it’s all relatively sober. Over a period, the overall result is a significant calorie deficit across the week, allowing a steady level of weight loss. If regularly maintained in this way, intermittent fasting using the 5:2 diet could help to lose weight.
Long term benefits of fasting through the 5:2 diet
More than just a weight loss strategy, the new interest in fasting hails the diet as a complete panacea for long term well being – with benefits across all aspects of health, including cognitive health, improving immune function and resisting disease. Studies into intermittent fasting have been supportive of these claims – with evidence suggesting intermittent fasting could reduce cognitive degeneration, improve cardiovascular health and manage or reduce the risk of diabetes. While such claims around a potential fad diet may seem far fetched, in this instance, the science behind the claims backs them up.
Eat less – to think faster and live longer
The potential health benefits of fasting lie in the impact of reducing food intake for short term periods, allowing a cycling effect with regular phases of each. Several studies on fasting have shown that the drastic calorie reduction for 2 days a week encourages the brain to protect itself, stimulating it at the cellular level to boost cell growth, and increasing resistance to plaque formation on neurons, that often underlies cognitive degenerative disorders such as Alzheimer’s or some dementias. And by introducing intermittent periods of stress to the body, many practitioners of fasting report feeling more alert, energetic and focussed, with the ability to concentrate for long periods greatly enhanced. This can potentially be attributed to the breakdown of body fat over continued fasts, as liver produces ketone bodies from fatty acids, which can be more easily used by the brain as fuel.
As well as the benefit to the brain, calorie restriction has been correlated with a reduced level of risk to developing certain cancers, cardiovascular disorders and diabetes. This may be because short periods of fasting improve the body’s responsiveness to insulin – a key hormone involved in the regulation of blood sugar. Other studies have shown fasters enjoying reduced symptoms of asthma and joint inflammation.
Fasting has also been suggested to have a variety of psychological benefits too, as the regular periods of discipline and restraint encourage greater focus and mindfulness, and is one of the reasons several religions across the world include fasting in some form as a regular practice. Though for many potential fasters across impulse-driven Western countries, the enforced restraint is one of the hardest obstacles of fasting to tackle.
Is the 5:2 diet right for everyone?
While early studies might show fasting to be enormously beneficial for many people, it’s important to be wary of potential fad dieting, and the sloppy, short-term goal-orientated approach many new fasters might be tempted to take. Seen as a cure all for everything from skin problems to cancer, it’s easy to pin your hopes on fasting as a instant solution.
Despite the flurry of attention, fasting is nothing new, and many people will continue to fast for a variety of reasons, once the spotlight fades away. While fasting has been suggested to be beneficial for most people, it should be avoided by the very young and old, as well as those with existing health symptoms, as the physical stress of calorie restriction can exacerbate health issues further. For those that are physically able to fast – the psychological pathway can often be far more complex. It’s also important to note one of the key tenets behind the principle of fasting – moderation. While it’s tempting to treat it as a short-term fix, fasting is better viewed as a step towards long term, and lasting, healthy living.
Books from the 5:2 diet creators
Here’s a couple of books you might be interested to get started:
#1 New York Times Bestseller – The FastDiet: Lose Weight, Stay Healthy, and Live Longer with the Simple Secret of Intermittent Fasting