BACKGROUND: The long-term efficacy and safety of time-restricted eating for weight loss are not clear.
METHODS: We randomly assigned 139 patients with obesity 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 primary outcome was the difference between the two groups in the change from baseline in body weight; secondary outcomes included changes in waist circumference, body-mass index (BMI), amount of body fat, and measures of metabolic risk factors.
RESULTS: 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 (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. Changes in weight were not significantly different in the two groups at the 12-month assessment (net difference, -1.8 kg; 95% CI, -4.0 to 0.4; P = 0.11). 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.
CONCLUSIONS: 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. (Funded by the National Key Research and Development Project [No. 2018YFA0800404] and others; ClinicalTrials.gov number, NCT03745612.).
|Special Interest - Obesity -- Physician|
|Family Medicine (FM)/General Practice (GP)|
|General Internal Medicine-Primary Care(US)|
Ideally, I would have liked to see the trial done without calorie restriction. In my practice, anecdotal data suggests it is useful.
Lots of interest among patients about diets based on intermittent fasting, so this is useful.
Results are not surprising. Same caloric intake over 24 hours = similar weight changes down the road. Intermittent fasting [19h00 (day 1)->11h00 (day 2)] without "making-up" the caloric intake skipped by the fasting would likely have different results in the real-world, and still lead to very adequate nutrition.
This study suggests it is not worth adding time restrictions to calorie restrictions. Regardless, from a Public Health perspective, other population- and policy-based interventions seem more relevant than specific adaptations to dietary restrictions.
The durability of the weight loss (12 mo) is good news and merits disseminating. Also, the similarity of weight loss between the two groups. It would be useful to have more information on energy expenditure and on the acceptability of the 2 interventions to participants. Clearly, more work is needed and this article should encourage more researchers to continue the hunt.
Interesting article on a diet and weight-loss program. Rigorous RCT that can inform practitioners about the best recommendation to patients. This study suggested that restricting eating time was not more effective than a low-calorie program alone.
Nice to see that clinical experience is supported by an RCT.