A one-year research in which participants ate a low-calorie diet between the hours of 8 am and 4 pm or consumed the same number of calories at any time of day found no effect, the study, published in New England Journal of Medicine on Thursday, revealed.
Researchers at Southern Medical University in Guangzhou, China, and the Tulane University School of Public Health and Tropical Medicine in the US have discovered that time-restricted eating, a type of intermittent fasting in which people only eat during a limited window of the day, has no substantial benefits in the fight against obesity when compared to basic calorie restriction.
A total of 139 overweight to substantially obese people in Guangzhou were divided into two study groups and observed for a year. Men were told to consume 1,500 to 1,800 calories per day, while women were told to consume 1,200 to 1,500 calories per day.
In the other group, men and women were directed to eat the same number of calories, but only between the hours of 8 am and 4 pm. Participants in the study were requested to keep meal diaries and photograph all of the food they ate in order to track their compliance.
To their joy, both groups lost weight towards the end of the year, ranging from 6.4 to 8.2 kilograms (14 to 18 pounds), but there was no significant difference in weight loss between the two groups while eating on a time-restricted schedule.
"Among patients with obesity, a regimen of time-restricted eating was not more beneficial with regard to reduction in body weight, body fat, or metabolic risk factors than daily calorie restriction," the study reads.
Other indicators of weight loss, such as BMI (body mass index, a popular means of assessing weight), waist circumference, body fat, or metabolic risk factors, including insulin resistance and blood pressure, showed no real effect.
Although this is not the first study to look into time-restricted eating, earlier studies were frequently smaller, shorter in duration, and lacked control groups. People lost weight by eating only for a short period of time during the day, according to those researchers.
According to a CNN report, time restriction had previously been found to have benefits in an earlier research. A study of human and animal research published in 2020 revealed that confining calories to a shorter period of the day offered health benefits, including lower blood pressure, weight loss, and increased longevity.