Study suggests that restricting food consumption to less than 8 hours a day may increase risk of cardiovascular death. More research needed for clear recommendations.

Recent research presented at the American Heart Association’s scientific sessions in Chicago challenges the widely-held belief that intermittent fasting is beneficial for heart health. The study conducted by researchers from Shanghai Jiao Tong University School of Medicine in China found that individuals who restricted their food consumption to less than eight hours per day had a 91% higher risk of dying from cardiovascular disease over a median period of eight years, compared to those who consumed food across a 12 to 16-hour window.

This analysis, based on data from the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey collected between 2003 and 2018, involved approximately 20,000 adults who recorded their food intake for at least two days. The researchers then examined the incidence of death from cardiovascular disease after the eight-year follow-up period.

The study’s co-author, Victor Wenze Zhong, emphasized caution in making specific recommendations about intermittent fasting based solely on this research. While short-term intermittent fasting may lead to weight loss and improvements in cardiometabolic health, Zhong advised against extended periods of fasting, such as over the course of several years.

Intermittent fasting strategies can vary widely, ranging from restricting eating to a six to eight-hour window per day to following the “5:2 diet,” which involves consuming 500 to 600 calories on two nonconsecutive days of the week. Despite the potential benefits attributed to intermittent fasting, this latest analysis raises concerns about the long-term implications on cardiovascular health.

Though the exact reason for the association between time-restricted eating and increased cardiovascular mortality remains unclear, one observation made by Zhong points to the correlation between restricted eating patterns and low lean muscle mass, which has been linked to a higher risk of cardiovascular death.

It is important to note that intermittent fasting has gained popularity in recent years as a weight loss strategy, with purported benefits ranging from weight loss to increased productivity. While some studies suggest potential longevity benefits associated with intermittent fasting, particularly in terms of disease prevention, the focus should remain on how intermittent fasting is implemented and its potential impact on overall health.

The research offers valuable insights into the potential risks of prolonged intermittent fasting, but further studies are warranted to fully understand the implications of this dietary approach on cardiovascular health. Our gratitude to the researchers and institutions involved in this important study.