Losing weight with intermittent fasting is becoming more and more popular (Picture: Getty)
People following a popular intermittent fasting diet nearly double their risk of dying from cardiovascular disease, according to a new study.
A preliminary study by the American Heart Association found that those who limit their eating to less than 8 hours a day were more likely to die from cardiovascular disease than those who ate 12-16 hours per day.
Time-restricted eating, a type of intermittent fasting, sees people limiting the time they eat to a specific number of hours a day, which could range from a four- to 12-hour window in 24 hours.
One common diet is the 16:8 schedule, where you eat for eight hours and ‘fast’ for 16, and has been used by celebrities such as Jennifer Aniston, Heidi Klum and Jennifer Lopez.
This way of eating is popular among those trying to lose weight, and studies have previously suggested that, short term, it can improve blood pressure, blood glucose, and cholesterol levels.
However, research on the long-term effects in limited.
To address that, researchers looked at 20,000 US adults with an average age of 49 years to investigate the long-term health impact of restricting eating to an eight-hour schedule.
They found that those who eat all their food across fewer than eight hours per day had a 91% higher risk of death due to cardiovascular disease.
Some intermittent fasts see people eating for less than eight hours a day (Picture: Getty)
For those with an existing cardiovascular disease, eating more than eight but less than 10 hours a day was associated with a 66% higher risk of death from heart disease or stroke.
‘We were surprised to find that people who followed an eight-hour, time-restricted eating schedule were more likely to die from cardiovascular disease,’ said senior author Dr Victor Wenze Zhong.
‘Even though this type of diet has been popular due to its potential short-term benefits, our research clearly shows that, compared with a typical eating time range of 12-16 hours per day, a shorter eating duration was not associated with living longer.’
Time-restricted eating did not reduce the risk of death from any cause.
‘It is crucial for patients, particularly those with existing heart conditions or cancer, to be aware of the association between an 8-hour eating window and increased risk of cardiovascular death,’ he said.
‘Our study’s findings encourage a more cautious, personalised approach to dietary recommendations, ensuring that they are aligned with an individual’s health status and the latest scientific evidence.
‘Although the study identified an association between an eight-hour eating window and cardiovascular death, this does not mean that time-restricted eating caused cardiovascular death.’
Cardiovascular disease: the lowdown
There are around 7.6 million people living with a heart or circulatory disease in the UK – 4 million men and 3.6 million women
In the UK there are around 100,000 hospital admissions each year due to heart attacks
More than a million people in the UK are living with heart failure
Strokes cause around 34,000 deaths in the UK each year and are the biggest cause of severe disability in the UK
Source: British Heart Foundation
The study followed participants for an average length of eight years and a maximum length of 17 years, and included data from National Health and Nutrition Examination Surveys participants who were at least 20 years old at enrollment.
Around half of the participants were men and roughly 73% of participants were non-Hispanic white adults, while 11% were Hispanic, 8% were non-Hispanic black adults, and just under 7% were from another racial category.
The study included information that was self-reported, which may be affected by the participant’s memory or recall, while other factors that may play a role in health outside of daily duration of eating and cause of death were not included in the analysis.
‘Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects,’ said Dr Christopher Gardner, a professor at Stanford University, who was not involved in the study.
‘When the study is presented in its entirety, it will be interesting and helpful to learn more of the details of the analysis.
‘One of those details involves the nutrient quality of the diets typical of the different subsets of participants. Without this information, it cannot be determined if nutrient density might be an alternate explanation to the findings that currently focus on the window of time for eating.’
The study is published in the American Heart Association Journal.