Effects Of 8-hour Time-restricted Eating With Exercise On Continuous Glucose Levels And Quality Of Life

PURPOSE: Recently, time-restricted eating (TRE) has become a popular nutrition strategy as it only requires limiting the eating time without controlling energy intake. However, limited studies have examined the combined effect of TRE and exercise. Therefore, this study examined the effect of 8-hour TRE, with or without exercise, on continuous glucose levels and quality of life in adults with central obesity. METHODS: We conducted a four-arm randomized controlled trial, including a control group, TRF group, exercise group, and TRE + exercise group, for 8 weeks. In total, we recruited 48 males with central obesity (age = 36.6 ± 6.8 years, body mass index [BMI] = 30.5 ± 3.3 kg/m2, waistline = 100.7 ± 8.2 cm) and randomly assigned them to one of the groups. Participants in the TRE group were required to eat ad libitum in a self-selected 8-hour eating window with 16-hour fasting. The exercise group was required to engage in 40 minutes of moderate brisk walking three times per week. Continuous glucose levels were monitored using the Freestyle Libre CGM, and the area under the curve (AUC) of interstitial glucose during a 24-hour period was calculated. Quality of life was assessed using the WHOQOL questionnaire. Two-way repeated ANOVA and paired t-tests were used for data analysis. RESULTS: After 8 weeks of intervention, participants in TRE (89.6 ± 8.1 vs. 88.1 ± 8.7 kg, p = 0.004) and TRE + Exercise (92.8 ± 10.7 vs. 91.0 ± 11.3 kg, p = 0.014) groups reduced their body weight. In addition, both the TRE (10.5 ± 1.9 vs. 7.1 ± 0.9 hours, p = 0.007) and TRE + Exercise (10.7 ± 2.9 vs. 6.8 ± 1.9 hours, p = 0.012) groups significantly reduced their eating window by postponing the first meal and finishing the last meal earlier. During the intervention, the mean 24-hour continuous glucose levels (AUC) were significantly lower in the TRE (133.5 ± 4.2 vs. 125.2 ± 11.4, p = 0.021) and TRE + Exercise (135.1 ± 3.5 vs. 129.6 ± 12.3, p = 0.038) groups than before the intervention. However, no significant difference was found in any domains of quality of life. CONCLUSION: TRE with or without exercise can significantly reduce body weight and continuous glucose levels, while 8 weeks may not be enough to change quality of life in adults with central obesity. This study adds more useful information on the combination of TRE and exercise to improve the metabolic health of the obese population. Health and Medical Research Fund (HMRF), Research Fund Secretariat of the Food and Health Bureau [20210521]