Experts have called for global nutritional guidelines to be changed to recommend we eat more fat and less carbohydrates after analysing a large-scale study.
Swiss scientists looked at the Prospective Urban Rural Epidemiology (PURE) research published in The Lancet in August.
It found that people who had a high-carbohydrate diet had a 28 percent higher risk of dying – and that eating more than the currently recommended amounts of fat was not linked to higher heart disease rates.
The findings call into question the long-held wisdom that people should limit total fat intake to less than 30 per cent of daily energy, and saturated fat to less than 10 per cent.
In fact, they support reducing carbs in favor of fats of all kinds, even saturated fats. They suggested that an intake of about 35 per cent of energy in fats.
The researchers argued cutting back on fats is no good for your health if you replace it with high levels of carbohydrates – an excess of which has been linked to diabetes.
Researchers argue cutting back on fats is no good for your health if you replace it with high levels of carbohydrates (stock image)
Saturated fat – found in butter, cheese, red meat and other animal-based foods – has for a long time been linked it to an increased risk of heart disease. But there are those that claim that fatty foods have been wrongly ‘demonised’.
Now experts from the Swiss Federal Institute of Technology, in a paper published the journal Cell Metabolism, wrote: ‘Taking the body of evidence into account, we believe that current nutritional recommendations in regards to macronutrients, but most importantly in regards to refined carbs and sugar, should indeed be fundamentally reconsidered.’
They also suggest that drugs that mimic lowcarb nutrition – that is without the need for an actual reduction of carbohydrate intake – may offer a ‘promising approach’ to fighting obesity.
What did PURE study find?
Previous studies on animals found that reducing overall calorie intake extends the lives of rodents and monkeys.
Since the 1970s, findings such as these has brought a focus on on reducing fats — especially saturated fats — to improve health and longevity. But the PURE research questioned this approach.
Over the course of about seven years, diets with roughly 35 percent of calories from fats were tied to a lower mortality rate than diets with about 60 percent of calories from carbohydrates.
Saturated fats have for a long time been linked it to an increased risk of heart disease – but some argue they’ve been unfairly ‘demonised’ (stock image)
The researchers found that people consuming the most carbs (over 70 per cent of total calories) died sooner than those compared to those with the lowest levels.
The PURE authors claim moderate intakes of carbohydrates (around 50-55% of total energy) are likely to be more appropriate than either very high or very low carbohydrate intakes.
They also recommend around three to four servings of fruit or vegetables per day.
‘What we are suggesting is moderation as opposed to very low and very high intakes of fats and carbohydrates,’ said Mahshid Dehghan from McMaster University in Hamilton, Ontario, Canada.
Other evidence for lower carbs
The Swiss researchers point out that several animal studies have shown how high levels of carbohydrates could be harmful.
Glucose is a type of sugar you get from foods you eat, and your body uses it for energy. Insulin is a hormone that moves glucose from your blood into the cells for energy and storage.
In type 2 diabetes, the body becomes insensitive to insulin and it cannot regulate the amount of glucose in the blood. This can lead to a life-threatening complications.
The theory goes that dietary carbohydrates increase mortality, so reducing intake, or inhibiting their uptake and metabolism in the body, should boost health and longevity.
The Swiss researchers note that this has been seen in some animal studies – because of the breakdown of glucose or glucose absorption from the gut.
Drugs which speed up glucose excretion in the urine or reduce the liver’s glucose production may be beneficial, but further studies are needed to confirm this, they said.
What do the critics of PURE say?
DRUG COULD BE EFFECTIVE AS ATKINS DIET – WITHOUT RISKS
High-protein diets are known to keep us feeling fuller for longer – and now scientists believe they understand why.
They have discovered its down to an amino acid found in protein that triggers the release of appetite-suppressing hormones in the gut.
It is hoped the findings may lead to a treatment that can mimic a high-protein diet, which can be difficult to maintain and come with numerous health risks.
These include constipation due to a lack of dietary fibre, increased risk of heart disease – because of higher red meat consumption – and concerns about kidney damage.
Experts now say the compound phenylalanine could be used in the fight against obesity.
Nearly a third of the world’s population is now overweight or obese, according to World Health Organisation (WHO) figures.
The Swiss researchers explain that some critics argue the PURE researchers looked at ‘total carbohydrates’ and did not distinguish between refined and unrefined types – which have different effects on health.
It was also pointed out that a diet very high in carbohydrates and low in fat may be due to a ‘poverty diet’ in people who cannot afford to eat meat.
Indeed, higher mortality rates may therefore be more related to economic hardship rather than directly related to diet.
Dr Frank Hu, chair of the department of nutrition at the Harvard Chan School of Public Health, said that people should look beyond the sensational headlines.
‘The main messages for nutritional advice have not changed,’ he said. ‘Follow a healthy dietary pattern that includes abundant amounts of vegetables, fruits, whole grains, legumes, and nuts; moderate amounts of reduced-fat dairy products and seafood; and lower amounts of processed and red meat, sugar-sweetened foods and beverages, and refined grains.
‘Such a dietary pattern does not need to limit total fat intake but the main types of fat should be unsaturated fats from plant sources rather than animal fat.’