Effectiveness of Early Time-Restricted Eating for Weight Loss, Fat Loss, and Cardiometabolic Health in Adults With Obesity: A Randomized Clinical Trial.
Level 2 - randomized trial
Individual randomized clinical trial
PubMed 35939311 · doi:10.1001/jamainternmed.2022.3050
What was done
Ninety adults aged 25 to 75 with obesity (mean BMI 39.6; 80% female) receiving weight-loss counseling were randomized in a 14-week parallel-arm trial to early time-restricted eating with energy restriction (eTRE+ER; 8-hour eating window from 7:00 to 15:00) or control eating with energy restriction (CON+ER; eating window ≥12 hours). Co-primary outcomes were weight loss and fat loss. Secondary endpoints included blood pressure, heart rate, glycemic markers, lipids, mood, physical activity, and sleep.
What was found
Participants in the eTRE+ER arm adhered an average of 6.0 days per week. Compared to CON+ER, eTRE+ER led to significantly greater weight loss (-2.3 kg; 95% CI, -3.7 to -0.9 kg; P = .002), equivalent to an additional caloric deficit of 214 kcal/day. In the primary intention-to-treat analysis, eTRE+ER did not significantly reduce body fat (-1.4 kg; 95% CI, -2.9 to 0.2 kg; P = .09) or fat-to-weight loss ratio (-4.2%; 95% CI, -14.9% to 6.5%; P = .43), though fat and trunk fat reductions were significant in a secondary completer analysis (n = 59). eTRE+ER also reduced diastolic blood pressure (-4 mm Hg; 95% CI, -8 to 0 mm Hg; P = .04) and improved mood metrics (fatigue-inertia, vigor-activity, depression-dejection). Other cardiometabolic markers, reported food intake, physical activity, and sleep did not differ between groups.
Why it matters
This study shows that confining food intake to an early 8-hour window enhances weight loss and modestly improves diastolic blood pressure and mood beyond standard caloric restriction alone.
Limits
Sample size was modest (n = 90) with high attrition (only 59 completers), limiting statistical power and leaving the primary fat-loss outcome non-significant. The trial was single-center, predominantly female (80%), and limited to 14 weeks, leaving long-term adherence and maintenance unmeasured.
Cited by
- supports Early time-restricted eating can produce a significant drop in blood pressure on the order of 10 mm Hg.