Intermittent fasting, a popular trend embraced by many seeking weight loss, has been found to potentially aid in shedding extra pounds in the short term. However, recent research presented at the American Heart Association’s event in Chicago suggests that this practice could have counterproductive effects, increasing the risk of death from heart attack and stroke in the long run.
The study, presented at the American Heart Association’s Epidemiology and Prevention Lifestyle and Cardiometabolic Scientific Sessions 2024, examined over 20,000 U.S. adults. It revealed that individuals who restricted their eating to less than an 8-hour window each day, a practice known as time-restricted eating, were more prone to cardiovascular disease-related deaths compared to those who spread their meals over a 12- to 16-hour period.
Time-restricted eating, a form of intermittent fasting, involves limiting daily food consumption to a specific number of hours, typically ranging from 4 to 12 hours within 24 hours. Many adherents follow a 16:8 eating schedule, consuming all meals within an 8-hour window, and fasting for the remaining 16 hours. Previous studies have indicated positive effects of time-restricted eating on various cardiometabolic health parameters such as blood pressure, blood glucose, and cholesterol levels.
Senior study author Victor Wenze Zhong expressed surprise at the findings, noting the practice’s increasing popularity as a means of weight management and heart health improvement. However, he cautioned that the long-term health implications, particularly the risk of cardiovascular disease-related mortality, remain uncertain.
The research analyzed data from the National Health and Nutrition Examination Surveys (NHANES) conducted between 2003 and 2018, along with mortality data from the Centers for Disease Control and Prevention’s National Death Index database up to December 2019. Key findings of the analysis included individuals adhering to a less than 8-hour daily eating window faced a 91% higher risk of death from cardiovascular disease. This increased risk persisted among individuals with pre-existing heart disease or cancer. Among those with existing cardiovascular disease, an eating window of 8 to less than 10 hours per day was associated with a 66% higher risk of death from heart disease or stroke.
However, time-restricted eating did not reduce the overall risk of death from any cause. Interestingly, an eating window exceeding 16 hours per day was linked to a lower risk of cancer mortality among individuals with cancer. Despite the association between an 8-hour eating window and cardiovascular death, Zhong emphasized that this does not imply causation. He stressed the importance of a cautious, personalized approach to dietary recommendations, considering individual health status and the latest scientific evidence.
The study’s limitations, such as reliance on self-reported dietary information and the exclusion of other health factors, underscore the need for further research to explore the biological mechanisms underlying the observed associations and their applicability across diverse populations.
In conclusion, while time-restricted eating may offer short-term benefits, its long-term effects warrant careful consideration. Future research should examine its potential impacts and guide dietary recommendations accordingly.
Reference
American Heart Association [Internet]. [cited 2024 Mar 20]. 8-hour time-restricted eating linked to a 91% higher risk of cardiovascular death. Available from: https://newsroom.heart.org/news/8-hour-time-restricted-eating-linked-to-a-91-higher-risk-of-cardiovascular-death