Does time-restricted eating add benefits to calorie restriction? A systematic review

ObjectiveA growing body of evidence has supported the health benefits of extended daily fasting, known as time-restricted eating (TRE); however, whether the addition of TRE enhances the known benefits of calorie restriction (CR) remains unclear.MethodsPubMed, Scopus, the Cochrane Library, and Google Scholar were searched through April 2023. This systematic review includes randomized controlled trials (RCTs) that compared CR + TRE with CR alone in energy-matched conditions of at least 8 weeks in duration that assessed changes in body weight and cardiometabolic disease risk factors in adults with overweight and/or obesity.ResultsSeven studies were identified (n = 579). Two studies reported greater weight loss and reductions in diastolic blood pressure with CR + TRE compared with CR alone after 8 to 14 weeks, whereas one study reported greater improvements in triglycerides and glucose tolerance with CR + TRE (3 d/wk) compared with CR alone following 26 weeks. One study reported significant increases in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels with CR + TRE versus CR alone after 8 weeks. There were no statistically significant differences in any other outcome variable between the two interventions.ConclusionsThe addition of TRE to CR regimens resulted in greater weight loss and improvements in cardiometabolic risk factors in some studies; however, the majority of studies did not find additional benefits.