Each weight-loss regimen had similar success in obesity management, regardless of patients reducing their calorie consumption through time-restricted eating or through calorie restriction alone.
New findings suggest a regimen of time-restricted eating for patients with obesity was not more beneficial in weight loss compared to a regimen of daily calorie restriction, with each resulting in similar caloric deficits.
Data show both regimens were noted to have similar effects with regards to reductions in body fat, visceral fat, blood pressure, glucose levels, and lipid levels over the 12-month study intervention.
“These results indicate that caloric intake restriction explained most of the beneficial effects seen with the time-restricted-eating regimen,” wrote study author Huijie Zhang, MD, PhD, Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University. “Even so, our findings suggest that the time-restricted–eating regimen worked as an alternative option for weight management.”
Previous studies did not report conclusive information to support evidence-based clinical guidelines for obesity. Additionally, the long-term efficacy and safety of time-restricted eating for weight loss is uncertain, as its effects compared with daily caloric restriction.
Trial participants in the current study were recruited from the general public and met eligibility criteria if they were 18 to 75 years old and had a body mass index (BMI) between 28 and 45. Within 12 months, male participants were instructed to follow a calorie-restricted diet of 1200 to 1500 kcal per day, while female participants were to follow a diet of 1200 to 1500 kcal per day.
The time-restricted eating restricted eating within an 8-hour period (from 8:00 am to 4:00 pm). Investigators defined adherence to the dietary program according to the number of days a participant met the requirements of the assigned diet.
The daily-calorie-restriction group were required to limit food consumption to the prescribed daily calories. Those in the time-restricted eating group were required to eat within the predefined time period and meet the caloric-intake goal.
From November 2018 - July 2021, a total of 139 participants were randomized to time-restricted eating (n = 69) or daily calorie restriction (n = 70). Then, only 118 (84.9%) participants completed the 12-month follow-up visit.
Over the 12-month interview, data report the mean percentage of days that participants adhered to both the prescribed calories and eating period was 84.0±16.1% in the time-restricted eating group and 83.8±12.6% in the daily-calorie restriction group.
Then, the mean weight change from baseline at 12 months was -8.0 kg (95% confidence interval [CI], -9.6 to -6.4) in the time-restriction group and -6.3 kg (95% CI, -7.8 to -4.7) in the daily-calorie restriction group.
Investigators saw no significant difference between the two groups in weight change (net difference, -1.8 kg; 95% CI, -4.0 to 0.4; P = .11).
Further, the body fat mass at 12 months was reduced by 5.9 kg (95% CI, -7.1 to -4.7) from baseline in the time-restricted eating group and by 4.5 kg (95% CI, -5.6 to -3.3) in the daily-calorie restriction group, showing no substantial differences between the groups.
There were additionally no substantial differences between each group regarding the number of adverse events reported during the trial.
The study, “Calorie Restriction with or without Time-Restricted Eating in Weight Loss,” was published in The New England Journal of Medicine.