Common weight loss strategies that limit the amount of time you can consume calories can nearly double your long-term risk of dying from cardiovascular disease, especially for people with underlying cardiovascular disease or cancer. A new study has revealed something.

But questions remain about how time-restricted diets, which restrict calorie consumption to a portion of the day, affect heart disease and stroke risk. Previous research suggests that dietary patterns may lower cardiovascular risk factors in the short term.

The new study is compelling, but it’s unclear why the participants chose this eating style, says Kenneth Mukamal, a primary care physician at Beth Israel Deaconess Medical Center and a professor at Harvard Medical School in Boston. the doctor said. Mukamal was not involved in the study, which was presented Monday at the American Heart Association’s Epidemiology, Prevention, Lifestyle, and Cardiometabolic Health Conference in Chicago.

“This was a reasonable effort to examine the long-term effects of time-restricted eating,” he says. “At first glance, it seems unlikely that this would be beneficial to cardiovascular health, and in fact it was harmful. However, eating in a time-restricted manner has health reasons and is not harmful. It may appear harmful.”

Mukamal said it’s premature to conclude that people should avoid time-restricted eating if it helps them achieve their weight loss goals. “At this point, if people want to eat in a shorter period of time and it’s easier to maintain their weight that way, I wouldn’t use that as a reason not to do it,” he said.

A type of intermittent fasting, time-restricted eating typically limits calorie intake to a range of 4 to 12 hours. Previous research has shown that it may be an effective weight loss strategy, especially when combined with calorie restriction. Research also suggests that it may reduce blood pressure and other important indicators of cardiovascular disease in obese people in the short term.

In the new study, researchers analyzed dietary data from a national survey of 20,078 U.S. adults with an average age of 49. In two cases, they recalled all the food and drinks they had consumed within 24 hours.

People who restricted their daily meals to less than eight hours were almost twice as likely to die from cardiovascular disease, including heart disease and stroke, within a median follow-up of eight years compared to those who ate meals. It takes 12 to 16 hours. An 8-hour meal window was associated with increased cardiovascular mortality in the general population as well as in people with pre-existing cardiovascular disease or cancer.

Time-restricted eating did not appear to affect the risk of death from all causes combined or cancer specifically. However, for cancer patients, eating for more than 16 hours a day was associated with a lower risk of death from cancer.

The findings are considered preliminary until the full results are published in a peer-reviewed journal.

Dr. Victor Wenze Zhong, professor and principal investigator in the Department of Epidemiology and Biostatistics at Shanghai Jiao Tong University School of Public Health in China, said the discovery surprised his team.

“Restricting your daily eating time to a short period of time, such as eight hours, has recently become popular as it is thought to help you lose weight and improve cardiometabolic health,” Zhong said. . “We therefore expected that the long-term introduction of an 8-hour time-restricted diet would be associated with a reduced risk of cardiovascular disease mortality and even all-cause mortality. We found that this was not the case. We were surprised to learn that.”

But Mukamal said many factors remain unclear.

“It’s important to note that it’s people who are choosing these dietary patterns,” he said, noting that this is an observational study, where people are assigned diets to different time periods for comparison. He pointed out that it was not a randomized trial. For example, cancer patients may suffer from loss of appetite and end up eating at more restricted times, but their life expectancy may be shortened.

“Part of what appears to be harmful may be due to the reasons why people choose to eat this way,” Mukamal says.

But even among the general population who chose to eat during restricted hours, there was “no clear cardiovascular benefit,” he said. “This leaves open any doubt as to whether time-restricted eating has the potential to improve cardiovascular health in the long term.”

Although research continues, people seeking healthier eating patterns should follow eating patterns that have been proven to improve heart health, Mukamal said. According to the AHA’s scientific statement, the DASH (Dietary Approaches to Stop Hypertension), pescetarian, and Mediterranean diets have the highest scores for heart health.

“At least for now, it’s less important to focus on when people eat and more important to focus on what they eat,” Mukamal says.