At a time when intermittent fasting has become a highly preferred and viable option for weight loss, eight hours of time-restricted eating or intermittent fasting may be the reason for a 91% higher risk of cardiovascular death, according to a study by the American Heart Association .

The study, conducted on more than 20,000 U.S. adults with an average age of 49, said people who restricted their food intake to less than eight hours per day had a higher risk of developing cardiovascular disease die when people who eat a cross diet 12-16 hours a day.

“Restricting daily eating time to a short period of time, such as 8 hours per day, has gained popularity in recent years as a way to lose weight and improve heart health. However, the long-term health effects of time-restricted food intake, including risk of death from any cause or cardiovascular disease, are unknown,” says Victor Wenze Zhong, senior study author and chair of the Department of Epidemiology and Biostatistics at Shanghai Jiao School of Medicine Tong University in Shanghai, China.

According to Zhong, although the study found a link between the eight-hour eating window and cardiovascular death, there is no evidence that time-restricted eating is the cause of cardiovascular death. “Overall, this study suggests that time-restricted eating may have short-term benefits but long-term negative effects,” says Christopher D. Gardner, Ph.D., FAHA, Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford. California.

Time-restricted eating is a form of intermittent fasting in which the hours of food intake are limited to a specific number of hours per day. The restricted time can range from 4 to 12 hours and 24 hours. With the growing popularity of intermittent fasting, many people are following a 16:8 eating plan, where they eat in an 8-hour window and fast for the remaining 16 hours each day.

The study also shows that people with previous heart disease have an increased risk of cardiovascular disease. In people with existing cardiovascular disease, eating for at least 8 but less than 10 hours per day was also associated with a 66% higher risk of dying from heart disease or stroke, according to the study. Time-restricted eating did not reduce the overall risk of death from any cause. Eating for more than 16 hours per day was associated with a lower risk of cancer mortality in cancer patients. “It is critically important for patients, especially those with existing heart disease or cancer, to be aware of the association between an 8-hour eating window and an increased risk of cardiovascular death,” says Zhong.

In particular, the study limits the inclusion of nutritional quality of the diet and other factors such as stress, demographic, cardiometabolic risk factors, and other factors associated with adverse cardiovascular outcomes.