An analysis of more than 20,000 American adults found that people who limited their eating to less than 8 hours a day, a time-restricted eating plan, were more likely to die from cardiovascular disease compared to people who ate between 12 and 16 hours per day. according to preliminary research presented at the American Heart Association’s 2024 Prevention and Epidemiology Cardiometabolic and Lifestyle Scientific Sessions, March 18-21 in Chicago. The meeting offers the latest scientific advances on the health and well-being of the population and its implications for lifestyle.
Time-restricted eating, a type of intermittent fasting, involves limiting eating times to a specific number of hours each day, which can range from 4 to 12 hours in 24 hours. Many people who follow a time-restricted eating diet follow a 16:8 eating schedule, in which they eat all their food in an 8-hour period and fast for the remaining 16 hours each day, the researchers noted. Previous research has found that time-restricted eating improves several measures of cardiometabolic health, such as blood pressure, blood glucose, and cholesterol levels.
“Restricting daily eating time to a short period, such as 8 hours per day, has gained popularity in recent years as a way to lose weight and improve heart health,” said the study’s lead author, Victor Wenze Zhong, Ph.D., professor. and chairman of the department of epidemiology and biostatistics at Shanghai Jiao Tong University School of Medicine in Shanghai, China. “However, the long-term effects of time-restricted feeding are unknown, including the risk of death from any cause or cardiovascular disease.”
In this study, researchers investigated the possible long-term health impact of following a restricted 8-hour eating plan. They reviewed information on the dietary patterns of participants in the annual 2003-2018 National Health and Nutrition Examination Surveys (NHANES) compared to data on people who died in the US, from 2003 to December 2019. , from the Center for Disease Control and Prevention. Death Index Database.
The analysis found:
- People who followed a pattern of eating all their food in less than 8 hours a day had a 91% increased risk of death from cardiovascular disease.
- The increased risk of cardiovascular death was also seen in people who had heart disease or cancer.
- Among people with existing cardiovascular disease, eating for no less than 8 but less than 10 hours per day was also associated with a 66% increased risk of death from heart disease or stroke.
- Time-restricted eating did not reduce the overall risk of death from any cause.
- Eating more than 16 hours a day was associated with a lower risk of cancer mortality among people with cancer.
“We were surprised to find that people who followed an 8-hour, time-restricted eating schedule were more likely to die from cardiovascular disease. Although this type of diet has been popular because of its potential short-term benefits, our research clearly shows that compared with a typical eating schedule of 12 to 16 hours per day, shorter eating duration was not associated with longer life,” Zhong said.
“It is crucial that patients, particularly those with existing heart disease or cancer, are aware of the association between an 8-hour feeding period and an increased risk of cardiovascular death. Our study findings encourage a more cautious and personalized approach to dietary recommendations, ensuring they are aligned with an individual’s health status and the most recent scientific evidence,” he continued. “Although the study identified an association between an 8-hour eating period and cardiovascular death, this does not mean that time-restricted eating caused cardiovascular death.” Study details and background:
- The study included approximately 20,000 adults in the US with an average age of 49 years.
- Study participants were followed for a median of 8 years and a maximum duration of 17 years.
- The study included data from NHANES participants who were at least 20 years old at enrollment, between 2003 and 2018, and who had completed two 24-hour dietary recall questionnaires during the first year of enrollment.
- Approximately half of the participants identified as men and the other half as women. 73.3% of participants identified as non-Hispanic white adults, 11% identified as Hispanic adults, 8% identified as non-Hispanic black adults, and 6.9% of adults identified as other racial category , including the mixed one. -race adults and adults of other non-Hispanic races.
Limitations of the study included its reliance on self-reported dietary information, which may be affected by participant memory or recall and may not accurately assess typical eating patterns. Factors that may also influence health, other than daily meal duration and cause of death, were not included in the analysis.
Future research can examine the biological mechanisms underlying the associations between a restricted eating schedule and adverse cardiovascular outcomes, and whether these findings are similar for people living in other parts of the world, the authors noted.
“Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects. When the study is presented in full, it will be interesting and useful to know more details of the analysis.” said Christopher D. Gardner, Ph.D., FAHA, Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford, California, and chair of the writing committee for the Association’s 2023 scientific statement, Popular Dietary Patterns: Alignment with the American Heart Association 2021. Dietary Guidance.
“One of those details has to do with the nutrient quality of the typical diets of different subsets of participants. Without this information, it cannot be determined whether nutrient density could be an alternative explanation to the findings currently focused on.” in the eating time window. Secondly, it is necessary to emphasize that the categorization into the different time-restricted eating windows was determined on the basis of only two days of dietary intake,” he said.
“It will also be critical to see a comparison of demographic and baseline characteristics between the groups that were classified into the different time-restricted feeding windows; for example, was the group with the shorter time-restricted feeding window unique? compared to people who followed other eating schedules, in terms of weight, stress, traditional cardiometabolic risk factors, or other factors associated with adverse cardiovascular outcomes? This additional information will help better understand the possible independent contribution of the restricted eating pattern in the short time reported in this interesting and provocative abstract.”