A large study conducted in 18 countries suggests that it is not the fat in the diet that raises a person's risk for premature death. Consuming too many carbohydrates, particularly refined and processed carbs, appears to be the real culprit.

Diet Study Involves More Than 135,000 Individuals From 18 Countries

In the study involving over 135,000 individuals between 35 and 70 years old from 18 different countries, Mahshid Dehghan, from the Population Health Research Institute of McMaster University in Canada, and colleagues found that high carbohydrate intake is associated with worse total mortality and non-cardiovascular mortality outcome. High fat intake, on the other hand, is linked to a lower risk.

Risks Of Low-Fat, High-Carb Diet

In the study, individuals whose fat intake comprised about 35 percent of their daily diet were found to have 23 percent reduced risk of premature death and 18 percent lower odds for stroke compared with those who ate less fat. Dehghan and colleagues also noted that very low intake of saturated fat equivalent to below 3 percent of the daily diet was linked to a higher risk of death compared with diets that contain up to 13 percent saturated fat.

Those whose diets are comprised of 77 percent carbohydrates were likewise found to have 28 percent higher risk of death than those on low-carb diets.

Global Dietary Guidelines Need To Be Reconsidered

Based on their findings, the researchers said that global dietary guidelines need to be reconsidered. Current guidelines recommend that between 50 and 65 percent of a person's daily calories should be from carbohydrates and less than 10 percent should come from saturated fats.

"High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke," the researchers wrote in their study, which was published in the journal The Lancet on Aug. 29.

Lowering Carbohydrate Intake May Reduce Risk Of Premature Death

Dehghan said that those with high carbohydrate intake of more than 60 percent of energy may benefit from increasing fat consumption and reducing intake of carbohydrates. Rice, breads and cereals are examples of high-carb foods.

"Limiting total fat consumption is unlikely to improve health in populations, and a total fat intake of about 35 percent of energy with concomitant lowering of carbohydrate intake may lower risk of total mortality," Dehghan said.