A diet high in carbs may just kill you, according to a new study from researchers at McMaster University in Ontario.
The study examined 135,000 people across five continents and found a diet that includes a moderate intake of fat, fruits and vegetables, and avoidance of high carbohydrates, is associate with lower risk of death. Specifically, the lowest risk of death was in those people who consume three to four servings of fruits, vegetables and legumes a day. What’s more, consumer a higher amount of fat is associated with a lower risk of death compared to lower intakes. And while a diet high in carbohydrates may not increase the risk of cardiovascular disease, it is linked to higher mortality rates.
Researchers found that fats of all kinds (saturated, polyunsaturated and mono unsaturated) was linked to lower mortality rates, with saturated fats being associated with lower stroke risk.
The new study, when viewed in the context of most previous studies, questions the conventional beliefs about dietary fats and clinical outcomes, says Mahshid Dehghan, the lead author for the study and an investigator at PHRI.
"A decrease in fat intake automatically led to an increase in carbohydrate consumption and our findings may explain why certain populations such as South Asians, who do not consume much fat but consume a lot of carbohydrates, have higher mortality rates," she said in a statement.
Dehghan pointed out that dietary guidelines have focused for decades on reducing total fat to below 30 percent of daily caloric intake and saturated fat to below 10 percent of caloric intake. This is based on the idea that reducing saturated fat should reduce the risk of cardiovascular disease, but did not take into account how saturated fat is replaced in the diet.
She added that the current guidelines were developed about four decades ago using data from some Western countries, where fat was more than 40 percent or 45 percent of caloric intake and saturated fat intakes were more than 20 percent. The consumption of these are now much lower in North America and Europe (31 percent and 11 percent respectively).
When it comes to fruit, vegetable and legume consumption, researchers also found that the common dietary guideline of a minimum of five daily servings may not be achievable for those in lower-income regions in the world. However, just three to four servings is still beneficial, according to researchers.
"Our study found the lowest risk of death in those who consumed three to four servings or the equivalent to 375 to 500 grams of fruits, vegetables and legumes per day, with little additional benefit for intake beyond that range," said Victoria Miller, a McMaster doctoral student and lead author of the paper where the research was published. "Additionally, fruit intake was more strongly associated with benefit than vegetables.”