Consuming Food Restricted By Time May Eventually Increase The Risk of Cardiovascular Mortality

According to recent research, persons who follow a popular weight loss plan that restricts the number of hours they can consume calories may nearly quadruple their long-term risk of dying from cardiovascular disease, particularly if they already have cancer or cardiovascular disease.

However, it’s still unclear how exactly time-restricted eating, which restricts calorie intake to certain hours of the day, influences the risk of heart disease and stroke. Previous research has indicated that the eating pattern may temporarily reduce cardiovascular risk factors.

Although the new data is persuasive, Dr. Kenneth Mukamal, a primary care physician at Beth Israel Deaconess Medical Center and a medical professor at Harvard Medical School in Boston, stated that it is unknown why participants choose this eating pattern. The study was presented Monday at the Epidemiology, Prevention, Lifestyle, and Cardiometabolic Health meeting of the American Heart Association in Chicago; Mukamal was not involved in its creation.

“This was a reasonable effort to look at long-term effects of time-restricted eating,” he said. “At first glance, it does not suggest this is likely to be of cardiovascular benefit and indeed it was harmful. But there could be health reasons to eat in a time-restricted manner that would make this appear harmful, when it’s not.”

According to Mukamal, it is premature to draw the conclusion that, even if time restriction aids in weight loss, people should avoid it. “At this point, if people want to eat over a shorter duration and it’s easier for them to maintain their weight that way, I would not use this as a reason not to do it,” he stated.

One kind of intermittent fasting called time-restricted eating limits the amount of calories consumed to a period of four to twelve hours. It may be a useful weight loss tactic, according to earlier research, especially when paired with calorie restriction. Additionally, research has indicated that in obese individuals, it may quickly drop blood pressure and other important markers of cardiovascular disease.

In the new study, researchers examined dietary information from a nationwide survey of 20,078 persons in the United States who, on average, were 49 years old. They were able to recollect everything they ate and drank in a 24-hour period twice.

During a median follow-up of eight years, the risk of dying from cardiovascular disease, which includes heart disease and stroke, was nearly twice as high for people whose eating was restricted to less than eight hours per day as for those whose meals were spread over twelve to sixteen hours. In both the general population and those with pre-existing cancer or cardiovascular illness, the eight-hour meal window was linked to increased cardiovascular mortality.

Eating under a time constraint did not seem to have an impact on the chance of dying from cancer in particular or from all causes combined. However, eating for more than 16 hours a day was linked to a decreased risk of cancer-related death in individuals with the disease.

Until the whole results are released in a peer-reviewed publication, the findings are regarded as preliminary.

The results shocked his colleagues, according to lead researcher Dr. Victor Wenze Zhong, a professor and chair of the epidemiology and biostatistics department at Shanghai Jiao Tong University School of Public Health in China.

“Restricting daily eating time to a short period, such as eight hours, has gained popularity recently because it seems to help people lose weight and improve cardiometabolic health,” Zhong said. “Thus, we had expected that long-term adoption of eight-hour time-restricted eating would be associated with lower risk of cardiovascular death and even all-cause death. We were surprised to find that (wasn’t the case).”

However, according to Mukamal, a lot of elements are still unknown.

He pointed out that the study was observational rather than randomized, meaning participants were not assigned to eat at different times for comparison. “It’s important to note these are people choosing this eating pattern,” he said. Individuals diagnosed with cancer, for instance, may experience a decrease in appetite and, as a result, eat less frequently, yet their life expectancy may be shortened.

“Some of what appears to be harmful may be due to the reasons why people are choosing to eat this way,” Mukamal stated.

But “there wasn’t any clear cardiovascular benefit,” he said, even among members of the general public who elected to eat within limited times. “This leaves quite open the question about whether time-restricted eating is likely to improve cardiovascular health in the long run.”

People seeking better eating habits should stick to those that have been shown to enhance heart health while research on the subject is ongoing, according to Mukamal. An AHA scientific statement states that the diets that score highest for heart health are the Mediterranean, pescatarian, and DASH (Dietary Approaches to Stop Hypertension) diets.

“At least as of now, focusing on what people eat is more important than focusing on the time in which they eat,” Mukamal stated.