A recent study has cast doubt on the purported health advantages of intermittent fasting, a popular dietary trend often endorsed by celebrities and wellness advocates alike.
Intermittent fasting involves consuming all food within an eight-hour window and abstaining from eating for the remaining 16 hours of the day. However, research published by the American Heart Association on March 18th has revealed a concerning association between limiting eating to an eight-hour window and a significant increase in the risk of death from heart disease.
Led by Dr. Victor Zhong of the Shanghai Jiao Tong University School of Medicine, the study examined approximately 20,000 adults in the United States, with an average age of 49 years, who had adopted intermittent fasting, specifically following the 16:8 plan.
Presented at the AHA’s Epidemiology and Prevention conference in Chicago, Illinois, the study found that individuals restricting their eating to an eight-hour window each day were 91 percent more likely to die from cardiovascular disease compared to those who consumed their meals over 12 or 16 hours. Moreover, among participants with pre-existing cardiovascular disease, an eating duration ranging from eight to 10 hours per day was associated with a 66 percent higher risk of death from heart disease or stroke.
Interestingly, individuals with cancer who extended their eating period beyond 16 hours were found to be less likely to succumb to the disease. Despite these findings, the study did not find evidence of a reduction in the overall risk of death from any cause.
Dr. Zhong, senior study author, commented on the surprising results: “Restricting daily eating time to a short period, such as eight 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 eating, including risk of death from any cause or cardiovascular disease, are unknown.”
He further elaborated, stating, “We were surprised to find that people who followed an eight-hour, time-restricted eating schedule were more likely to die from cardiovascular disease. Even though this type of diet has been popular due to its potential short-term benefits, our research clearly shows that, compared with a typical eating time range of 12-16 hours per day, a shorter eating duration was not associated with living longer.”
The study analyzed data from participants in the 2003-2018 National Health and Nutrition Examination Surveys, cross-referencing it with the Centers for Disease Control and Prevention’s National Death Index database. However, researchers acknowledged limitations in the study’s reliance on self-reported dietary information and the lack of focus on other factors potentially influencing participants’ health.
Dr. Christopher D. Gardner, the Rehnborg Farquhar Professor of Medicine at Stanford University, provided additional insight: “Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects. It will be interesting and helpful to learn more details of the analysis.”
He emphasized the importance of considering the nutrient quality of participants’ diets and the need for a more comprehensive assessment of factors influencing cardiovascular outcomes.
As the study awaits further analysis, researchers and healthcare professionals are eager to explore the broader implications of these findings and consider potential adjustments to dietary recommendations for optimal health outcomes.