A high-carb diet is worse for you than a high-fat one according to new research. Photo/File
A high-carb diet is worse for you than a high-fat one according to new research. Photo/File
People with high-carb diets are more likely to have health issues than those eating a high-fat diet, a major international study has found.
Results of the study, which involved more than 135,000 people from 18 countries over 10 years, were published in the Lancet today.
The research, led by McMaster University in Canada, found diets high in carbohydrates (people getting an average of 77 per cent of their energy from carbohydrates) had a 28 per cent higher risk of death compared to low carbohydrate diets (46 per cent energy from carbohydrates).
Comparatively, diets with high total fat intake (people getting 35.3 per cent of their energy from fat) had a 23 per cent lower risk of death compared to low fat diets (11 per cent energy from fat).
The Prospective Urban Rural Epidemiology study (PURE) found that on average, globally, people got more than 60 per cent of their energy from carbohydrates and 24 per cent from fats.
The participants were selected from 18 countries across the Middle East, South America, Africa, China, North America and Europe and South Asia.
Lead author Dr Mahshid Dehghan said the results suggested that rather than focusing on reducing fat intake in diets, guidelines should instead focus on reducing carbohydrate intake, particularly in low and middle-income countries where carbohydrate intake was highest.
While current guidelines recommended reducing saturated fat intake to below 10 per cent, the study found that getting less than 3 per cent of your energy from saturated fats was associated with a higher risk of mortality compared to people whose diets consisted of up to 13 per cent saturated fat.
"The best diets will include a balance of carbohydrates and fats - approximately 50-55 per cent carbohydrates and around 35 per cent total fat, including both saturated and unsaturated fats," Dehghan said.
"Despite there being no association between low carbohydrate intake and health outcomes, this does not provide support for very low carbohydrate diets - less than 50 per cent energy. A certain amount of carbohydrate is necessary to meet energy demands during physical activity and so moderate intakes, of around 50-55 per cent of energy, are likely to be more appropriate than either very high or very low carbohydrate intakes."
On average, carbohydrate intake was highest in China (67 per cent), South Asia (65.4 per cent) and Africa (63.3 per cent) while total fat intake was highest in North America and Europe (30.5 per cent), Middle East (30.3 per cent), and Southeast Asia (29.2 per cent).
During the study, 5796 people died (1649 from cardiovascular disease) and 4784 had a major cardiovascular disease event (2143 heart attacks and 2234 strokes).
Dehghan said cardiovascular disease was a global epidemic and diet was one of the most important modifiable risk factors for most non-communicable diseases.
New Zealand experts agreed that, while the findings were interesting, the best health advice was to eat a diet rich in vegetables and fruit, legumes, nuts, whole grains, meat and vegetable oils and limit the amount of free sugars, salt and highly processed food.
Professor Grant Schofield has long supported a high-fat, low-carb diet. Photo/File
Professor Grant Schofield, director of the Human Potential Centre at AUT, chief education adviser for health and nutrition and proponent of the high fat, low carb diet, said the study was part of a "sea-change" in establishment thinking about what constitutes a healthy diet.
"PURE tells us, along with mounting other evidence, that it is finally time to move on from banishing dietary fat, including saturated fat," he said.
The University of Otago's Professor Jim Mann, director of Edgar Diabetes and Obesity Research, warned there were "major limitations" to the conclusions drawn by the findings.
A key limitation was the lack of distinction between sugars and refined grains and fibre-rich carbohydrates like whole grains, fruit and vegetables, he said.
Other issues were the fact the most striking results were seen when comparing extreme levels of intake when most people did not fall into that category and the difference in diet between countries.
