Settling on a sensible diet has never been harder.
A civil war is raging in the world of nutrition, pitching proponents of fats into fierce academic conflicts with those who favour carbohydrates as the route to good health.
An opening shot (though he didn’t know it then) was fired in 2014 when a Merseyside GP put 19 patients who were overweight or had type 2 diabetes on a diet that flew in the face of conventional advice to go low fat with plenty of carbohydrates.
That was Dr David Unwin, who featured in the Mail’s recent series on type 2 diabetes. He advised his patients to reduce the amount of starchy carbs they ate, including bread, pasta, rice and root vegetables, but include some high-fat foods such as olive oil and butter.
Instead of an average of 300g carbohydrates a day, their intake dropped to between 20g and 50g (one croissant has about 25g).
What would you do? Growing evidence supports idea of switching between a keto, low-carb diet
But crucially, they didn’t have to cut calories. The lost carbs were replaced with foods rich in fat which reduced hunger. After eight months, the patients’ blood sugar levels came right down, and they’d lost on average 9kg.
Follow-up studies found that 40 per cent had reversed their type 2 diabetes and their levels of unhealthy blood fats (eg, LDL cholesterol) had dropped. And their energy levels improved.
This low-carb diet is similar to the increasingly popular ketogenic diet; keto recipe books are now bestsellers on amazon.co.uk. ‘Keto’ involves eating even fewer carbs, which helps you burn fat for fuel rather than glucose (good for weight loss) and also comes with reports of feeling more energetic.
Does this mean we should all start the low-carb or keto diet? It’s a controversial area. When it comes to the keto, some experts argue that eating so few carbs is harmful long term. Another concern is that this diet doesn’t provide enough fibre.
Meanwhile a U.S. study published earlier this year in The Lancet claimed that following such a diet could take four years off your life because of the increased amount of animal fats it involves.
However, keto diet supporters make a strong case, too, pointing to the repeated failure of trials of low-fat diets to show they cut the risk of heart disease.
Another potential benefit is the suggestion that keto may turn on the body’s repair and garbage collection system, called autophagy, which is found in every cell.
Divisive: A civil war is raging in the world of nutrition, pitching proponents of fats into fierce academic conflicts with those who favour carbohydrates as the route to good health
Cells generate a lot of waste — dead and damaged proteins. Without a regular clean-up they gradually become less efficient.
Meanwhile, a year-long study of 349 obese diabetic patients on a low-carb diet found 60 per cent ended up with healthy blood sugar levels and they lost an average of 12 per cent of their body weight. So, if you’re struggling to lose weight or are pre-diabetic, which warring camp should you join?
Well, what if you could follow a diet that had the benefits of cutting carbs but allowed you to eat some of the carb-rich foods (bread, potatoes) these dieters often miss?
There is growing evidence to support the idea of switching between a keto, low-carb approach — eating a few grams of carbohydrates a day plus a good amount of fats — and another form of low-carb approach (without the high dose of fats) which keeps your blood sugar down but allows you a much greater range of the carbohydrate foods you may be craving.
Both diets come with health benefits, including weight loss and an improvement of diabetic markers, but switching between them may boost these results — and make them more sustainable.
The idea of switching between more and less intense dietary regimens is being explored by Professor Valter Longo, a biologist and gerontologist at the University of California. He developed what he calls the fasting mimicking diet, designed to provide the benefits of calorie restriction, which include weight loss and a drop in the blood markers linked with type 2 diabetes or heart disease.
His regimen, tested in the lab and with clinical trials, starts with a strict calorie restriction for five days, where participants limit themselves to a low-carb, high-fat diet of fewer than 1,000 calories from vegan sources a day.
Both diets come with benefits, including weight loss and an improvement of diabetic markers, but switching between them may boost these results — and make them more sustainable
After five days, participants switch back to a regular vegan diet, with more carbs and less fat, for three weeks. They revert to the fasting
