Background: Time restricted eating (TRE) is a form of intermittent fasting that involves confining the period of eating to 8-h and fasting with zero-calorie beverages for 16-h. Short-term studies (2-3 month) suggest that 8-h TRE produces moderate weight loss and improves blood pressure and plasma lipids. What remains unknown is whether these improvements by TRE would become more pronounced over longer periods of time (6-months) , and whether these benefits are comparable to that of daily calorie restriction (CR) .
Objective: Accordingly, this study compared the effects of 8-h TRE versus CR and a no-intervention control group on body weight and cardiovascular disease risk factors in adults with obesity over 6-months.
Design: Adults with obesity (n = 63) were randomized to 1 of 3 interventions for 6-months: 8-h TRE (ad libitum eating between 12:00 to 8:00 pm, fasting between 8:00 to 12:00 pm) ; CR (25% energy restriction daily) ; or control (ad libitum food intake with no meal timing restrictions) .
Results: By month 6, body weight decreased (P = 0.02) by CR (-4.9 ± 1.4%) but not TRE (-3.4 ± 0.7%) , versus controls (-0.7 ± 1.1%) . Diastolic blood pressure was significantly (P = 0.04) reduced by TRE (-4.0 ± 1.4 mm Hg) , but not CR (-0.1 ± 1.7 mm Hg) , versus controls (1.6 ± 1.5 mm Hg) . Changes in systolic blood pressure, fat mass, visceral fat mass, lean mass, LDL cholesterol, HDL cholesterol, triglycerides, and heart rate did not differ between groups at month 6. Adherence to 8-h TRE remained high throughout the trial, i.e. subjects adhered to the 8-h eating window on 6 ± 0.1 days/week.
Conclusions: These preliminary findings suggest CR may produce greater weight loss compared to TRE over 6-months. While TRE did not produce significant weight loss, the diet did lower diastolic blood pressure. This would suggest that this intermittent fasting regimen may produce improvements in cardiovascular parameters in the absence of body weight reductions.
S. Lin: None. S. Cienfuegos: None. K. Gabel: None. K. Varady: None. A. Mulas: None.
NIH-NIDDK (1R01DK128180 - 01A1)