Eating low-carbohydrate diets may raise the risk of early death, claimed a study while noting that food products low in fat can prolong life.

Short-term clinical trials have shown the effectiveness of low-carbohydrate diets and low-fat diets for weight loss and cardiovascular benefits.

Low-fat diets include whole grain food, lean meat, reduced-fat dairy, vegetables, lentils and fruits.

Low-carbohydrate diets, on the other hand, restrict carbohydrate consumption relative to the average diet.

Foods high in carbohydrates are limited, and replaced with foods containing a higher percentage of fat and protein, as well as low-carbohydrate foods.

The study, led by an international team of researchers from the universities of Peking in China, Harvard and Tulane in the US, included 371,159 participants aged 50-71 years. The participants were followed for 23.5 years, and 165,698 deaths were recorded.

The findings, published in the Journal of Internal Medicine, showed that adopting a low-fat diet could slash the risk of death each year by up to 34 per cent.

Meanwhile, low-carb diets increased mortality risk by up to 38 per cent. People on keto-like diets were 28 per cent more likely to die from any cause when compared to their high-carb peers.

"Higher mortality was observed for overall low-carbohydrate diet and unhealthy low-carbohydrate diet, but slightly lower risks for healthy low-carbohydrate diet," the researchers wrote in the study.

"Our results support the importance of maintaining a healthy low-fat diet with less saturated fat in preventing all-cause and cause-specific mortality among middle-aged and older people," they added.

Moreover, following a healthy low-fat diet was associated with significantly lower total mortality by 18 per cent, cardiovascular mortality by 16 per cent, and cancer mortality by 18 per cent, respectively, versus the lowest.