This week, new scientific research linking intermittent fasting (IF) to an increased risk of cardiovascular disease has gained attention.

People who routinely eat for only eight hours each day and fast the rest of the day are twice as likely to die from a heart attack or stroke than those who eat for 12 to 16 hours. Research results show that there is. Obviously concerned.

IF has been popularized by celebrities such as Jennifer Aniston and Scarlett Johansson, and scientific studies have shown that IF improves not only weight loss but also short-term effects on blood pressure, blood sugar, and cholesterol, which are major causes of cardiovascular disease. It is also associated with improvement.

But a new study of a large group of people monitored over several years has revealed what the researcher and many others described as a “surprising” finding. In the long run, that diet could be doing people more harm than good.

The study involved 20,078 participants in the United States with an average age of 49 years and were followed for up to 17 years and an average of 8 years.

But scientists not involved in the study say the finding clearly highlights risks that require more thorough investigation, but should not be taken as good news, as it has a number of shortcomings. It is said that it is not.

“Big questions” about the results

To begin with, the study has not yet been peer-reviewed, a process in which scientists not involved in the study scrutinize its methodology and results.

Another fundamental problem with this study is that it was an “observational” study, meaning it identified associations rather than proving cause and effect.

The researchers “controlled” for factors that could have skewed the results, such as the participants’ age, income, BMI, blood pressure, and whether they drank or smoked, but rather than whether the participants were fasting. There may be a still unknown cause. I couldn’t think of anything.

However, it is relatively rare to demonstrate dietary causal relationships because it is difficult to control and monitor the food intake of large groups over long periods of time.

But perhaps the biggest problem with this study is that the researchers only looked at people’s eating habits for a total of two days, and assumed that they followed the same schedule for an average of eight years.

Sir David Spiegelhalter, Emeritus Professor of Statistics at the University of Cambridge, said:

“Specifically, why were those two specific days chosen to measure meal times? And how do we know if food was eaten outside the eight-hour window and simply wasn’t filled out in the questionnaire?” Is it possible to do this? [conference presentation] The summary should not have been accompanied by a press release. ”

Kevin McConway, emeritus professor of applied statistics at the Open University, added: “There are big questions about whether this study can show what it is supposed to show.”

“For example, we don’t know whether their meal times in these two 24-hour periods were the same as their usual meal times. Therefore, we do not know if these patterns were deliberately time-restricted over long periods of time. “The data seem to be far beyond linking it to dietary interventions,” he said.

Fasting is “not necessarily for health reasons”

Additionally, many of the people who completed the IF may have done it as needed rather than planned due to work schedules, which could lead to another bias in the survey results, the science says. They say:

Participants were participants in a broad and long-term national nutrition survey representative of the U.S. population, rather than those specifically enrolled to participate in the IF study.

“People who report having time restrictions for eating may be working antisocial hours, such as truck drivers, security guards, medical professionals, and night workers. This type of work practice “This is important because there is evidence that diabetes is associated with an increased risk of type 2 diabetes and cardiovascular disease,” said Tom Saunders, emeritus professor of nutrition at King’s College London.

It is also likely that at least some people are on strict dietary restrictions from their doctors because they are overweight, and others are choosing to restrict their diets because they are in poor health; have an increased risk of heart attack and stroke.

For example, cancer patients may suffer from loss of appetite, which may make eating time more restricted and shorten their life expectancy.

Duane Mellor, registered dietitian and senior lecturer at Aston University’s Aston School of Medicine, said:

“Some people do it for health reasons, while others do it because of stressful work conditions or poverty, both of which are risk factors for cardiovascular death.”

“Further research is needed.”

But scientists say the study highlights uncertainties that still exist in the burgeoning but little-known field of IF, both after the peer review process and on its own. He said that it definitely plays a role in that aspect. habit.

Professor Keith Fullen, from the University of Oxford, said: ‘Time-restricted eating is a popular way to reduce caloric intake, but its proponents claim other benefits such as ‘boosting metabolism’. ” This study is very important in demonstrating the need for long-term research into the effects of this habit. However, this summary leaves many questions unanswered and will require further research. ”

The study’s lead researcher, a professor at Shanghai Jiao Tong University, also agreed: “It is premature to conclude that time-restricted eating should be avoided.”

There’s still much we don’t understand about IF, but an important study from King’s College London found that eating all your food within 10 hours significantly improved your mood, increased your energy levels, and reduced your hunger. I found out that it will be done.

A study of 37,535 intermittent fasters found that nearly three-quarters of participants reported improved energy, 57 percent felt their mood improved, and 47 percent felt less hungry. Felt.

According to the researchers, IF gives the body, the intestinal lining, and the gut bacteria time to rest, recharge, and repair itself, but it does this effectively while a person is eating and digesting food. I can’t.

IF is also associated with weight loss, but as with all research on fasting, more research is needed.