Illinois — A recent analysis of more than 20,000 U.S. adults found that people who limited their eating across less than 8 hours per day, a time-restricted eating plan, were more likely to die from cardiovascular disease compared to people who ate across 12-16 hours per day, according to the American Heart Association.
Time-restricted eating, a type of intermittent fasting, involves limiting the hours for eating to a specific number of hours each day, which may range from a 4- to 12-hour time window in 24 hours. Many people who follow a time-restricted eating diet follow a 16:8 eating schedule, where they eat all their foods in an 8-hour window and fast for the remaining 16 hours each day, the researchers noted.
Despite the findings, it's important to note that there are many proven positive results from intermittent fasting. Previous research has found that time-restricted eating improves several cardiometabolic health measures, such as blood pressure, blood glucose and cholesterol levels.
“Studies have shown that intermittent fasting decreases blood pressure and sugars and helps prevent diabetes… so there’s some really positive things out there about intermittent fasting,” explained cardiologist Suzanne Steinbaum, MD.
Steinbaum pointed out that what people eat during their restrictive time is important to consider.
“If you have intermittent fasting, and then 8 hours of eating junk food – clearly that isn’t going to help,” said Steinbaum. “So the more nutrients, minerals and vitamins you get in your diet, that is what will sustain you and keep you healthy. I am not saying intermittent fasting is bad for you, but it isn’t for everyone.”
In this study, researchers investigated the potential long-term health impact of following an 8-hour time-restricted eating plan. They reviewed information about dietary patterns for participants in the annual 2003-2018 National Health and Nutrition Examination Surveys (NHANES) in comparison to data about people who died in the U.S., from 2003 through December 2019, from the Centers for Disease Control and Prevention’s National Death Index database.
The analysis found:
People who followed a pattern of eating all of their food across less than 8 hours per day had a 91% higher risk of death due to cardiovascular disease.
The increased risk of cardiovascular death was also seen in people living with heart disease or cancer.
Among people with existing cardiovascular disease, an eating duration of no less than 8 but less than 10 hours per day was also associated with a 66% higher risk of death from heart disease or stroke.
Time-restricted eating did not reduce the overall risk of death from any cause.
An eating duration of more than 16 hours per day was associated with a lower risk of cancer mortality among people with cancer.
Steinbaum said the study "didn't look at exactly what they were eating or if they had high blood pressure or stress or high sugars. It didn’t look at if they smoked.”
The study’s limitations included its reliance on self-reported dietary information, which may be affected by participant’s memory or recall and may not accurately assess typical eating patterns, according to the AHA.
“Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects. When the study is presented in its entirety, it will be interesting and helpful to learn more of the details of the analysis,” said Christopher D. Gardner, Ph.D., FAHA, the Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford, California.
Annie Gimbel
