Calorie restricted diet added to time-restriction fails to boost weight loss: NEJM
China: Time-restricted eating is an intermittent-fasting regimen that involves a shortened period of time for eating within each 24-hour period. It is a popular weight-loss strategy as it is simple to follow, which may enhance adherence.
A regimen of time-restricted eating is not more beneficial than daily calorie restriction with regard to reduction in body fat, body weight, or metabolic risk factors in patients with obesity.
The study, published in the New England Journal of Medicine found that obese patients who followed a time-restricted diet in addition to calorie restriction did not significantly lose a greater amount of weight compared to people who adhered alone to a calorie-restricted diet.
Peizhen Zhang, Southern Medical University, Guangzhou, China, and colleagues aimed to evaluate long-term efficacy and safety of time-restricted eating for weight loss.
For this purpose, the researchers randomly assigned 139 obese patients to time-restricted eating (eating only between 8:00 a.m. and 4:00 p.m.) with calorie restriction or daily calorie restriction alone. For 12 months, , all the participants were instructed to follow a calorie-restricted diet that consisted of 1500 to 1800 kcal per day for men and 1200 to 1500 kcal per day for women.
The difference between the two groups in the change from baseline in body weight was the primary outcome. Secondary outcomes included changes in waist circumference, amount of body fat, body-mass index (BMI), and measures of metabolic risk factors.
Salient findings of the study include:
- Of the total 139 participants who underwent randomization, 118 (84.9%) completed the 12-month follow-up visit.
- The mean weight loss from baseline at 12 months was −8.0 kg in the time-restriction group and −6.3 kg in the daily-calorie-restriction group.
- Changes in weight were not significantly different in the two groups at the 12-month assessment (net difference, −1.8 kg).
- Results of analyses of waist circumferences, BMI, body fat, body lean mass, blood pressure, and metabolic risk factors were consistent with the results of the primary outcome. In addition, there were no substantial differences between the groups in the numbers of adverse events.
"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 among patients with obesity," the authors wrote in their study.
Reference:
Liu D, Huang Y, Huang C, Yang S, Wei X, Zhang P, Guo D, Lin J, Xu B, Li C, He H, He J, Liu S, Shi L, Xue Y, Zhang H. Calorie Restriction with or without Time-Restricted Eating in Weight Loss. N Engl J Med. 2022 Apr 21;386(16):1495-1504. doi: 10.1056/NEJMoa2114833. PMID: 35443107.
