(NewsNation) — Intermittent fasting has become a popular weight loss plan in recent years, but research suggests it could increase the risk of dying from heart disease.

The American Heart Association’s study surveyed more than 20,000 adults and found that those who followed an eight-hour, time-restricted eating schedule, which is a type of intermittent fasting, had a 91% higher risk of death from heart disease compared to people who ate across 12-16 hours per day.

Intermittent fasting involves cycling between periods of fasting and eating, with variations such as eating every other day, fasting two days a week or limiting eating to specific hours each day. Time-restricted eating, where all daily meals are condensed into a window of 10-12 hours or less, is the most popular form.

While previous research from Johns Hopkins Medicine has shown that intermittent fasting improves health measures, such as blood pressure, blood glucose, and cholesterol levels, the AHA study showed that there was an increased risk of death from heart disease among people who were diagnosed with heart disease or cancer.

Among people who had heart disease, an eating duration of no less than eight hours but less than 10 hours daily was also associated with a 66% higher risk of death from heart disease or stroke.

“It’s crucial for patients, particularly those with existing heart conditions or cancer, to be aware of the association between an 8-hour eating window and increased risk of cardiovascular death,” senior study author Dr. Victor Wenze Zhong said. “Our study’s findings encourage a more cautious, personalized approach to dietary recommendations, ensuring that they are aligned with an individual’s health status and the latest scientific evidence.”

Zhong added that although a link between eight-hour, time-restricted intermittent fasting and death from heart disease exists, it does not suggest that time-restricted eating caused death from the disease.