Does eating like a caveman help you lose weight and live longer?

How it was told

A time long before Uber Eats, it was hard work getting fed when you were a caveman.

The hunter-gather aspect of grabbing your grub reportedly meant long periods of hunger briefly punctuated with a feast – but not too much lest it impact on their hunting skills.

Stories last week used the caveman analogy to describe the alternate fasting diet, which was the subject of a study led by scientists from the University of Graz. The academics tested the effects of 30 people eating normally for 12 hours out of 48 and fasting the rest of the time.

And their findings were largely hailed in the press.

The Telegraph and the Mail Online both joined the club when it came to caveman headlines. “Fasting every other day boosts healthy weight loss as it mimics hunter-gatherer ‘caveman’ routine” said The Telegraph while the Mail Online opted for: “Extreme ‘caveman’ diet of fasting every other day may help overweight patients lose nearly 8lbs in just FOUR WEEKS, scientists claim”.

The Times resisted the temptation to go for the caveman line but instead they went beyond the weight-shedding diet and said: “Alternate day fasting diet could be secret to
longer life”.

The Sun made a different claim, suggesting that when you have the licence to eat freely when you can. Their headline read: “FAST WORK: Lose weight fast with the ‘alternate day fasting diet’ – and eat what you want half the time”.

But are all those claims correct? And did cavemen really eat in this way?

Facts. Checked

This study does not show that fasting is the secret to a longer life but it does seem that it can help shed a few pounds. The researchers said that of all the anti-ageing and longevity-promoting interventions tested so far, calorie restriction seems the most effective. And fasting like in this study could be one of the best ways to reduce calorie intake by taking away the temptation of snacking.

It’s hard to read too much into the results of the study due to the sample size, which took 30 people who were fasting and 30 people to act as a control group over four weeks.

Rather than studying overweight people – as the Mail Online suggested – this study looked the effects of fasting on healthy humans with a BMI between 18.5 and 24.9 who had no health issues and drank no more than 15 alcoholic drinks per week.

During fasting periods, people were only allowed to drink water and unsweetened black or green tea or coffee, while it is unclear what exactly they ate when the shackles were off. However, The Sun’s claim that they could “gorge whatever tasty food they wanted” isn’t right – a balanced diet was deemed “crucial” by experts. The Sun was also wide of the mark when it came to ages – people between 35 and 65 were involved in the study, not the average age given in the paper of 48 to 52.

So the extreme diet isn’t quite what it is cracked up to be in some reports. But does it fit with how our cavemen ancestors used to eat?

The high-protein caveman diet – or the Paleo diet – focuses on eating things that are hunted and fished or gathered with the thinking that carbohydrates that form most of our diets will not have the chance to turn into fat. As for fasting, that is associated with the 5:2 diet – where you eat for five days and follow a low-calorie regimen for two.

However, as the NHS points out in its assessment of the Paleo diet, “There are no accurate records of the diet of our Stone Age ancestors, so the diet is based on educated guesses, and its health claims lack any scientific evidence”.

There remain risks of side-effects and a difficulty in hitting nutritional needs too – so it’s worth considering them before taking on the diets.

Image: Miles Cole