Effect of Time-Restricted Eating versus Daily Calorie Restriction on Mood and Quality of Life in Adults with Obesity.

The purpose of this secondary analysis is to compare the effects of two popular weight loss regimens, time-restricted eating (TRE) and daily calorie restriction (CR), on mood and quality-of-life measures in adults with obesity. Ninety participants were randomized to one of three interventions for 12 months: 8 h TRE (eating only between 12:00 and 8:00 p.m., with no calorie counting); CR (25% energy restriction daily); or no-intervention control group. Questionnaires were administered to measure mood (Beck Depression Inventory-II (BDI-II), and Profile of Mood States (POMS)) and quality of life (Rand 36-Item Short Form) at baseline and month 12. Body weight decreased in the TRE group (-4.87%, 95%CI: -7.61, -2.13) and CR group (-5.30%, 95%CI: -9.06, -1.54) versus controls, with no difference between TRE and CR. The BDI-II depression score did not change in the TRE or CR group, versus controls, by month 12. Likewise, there were no changes in any of the POMS subscales (tension, depression, anger, fatigue, anger, confusion, or vigor) or the total mood disturbance score in the TRE or CR group versus controls. As for quality of life, there were no significant changes in the SF-36 constructs of mental health, bodily pain, and general physical health in the TRE or CR group versus controls. However, there was a trend towards increased vitality in the TRE group (7.77 [95% CI: 0.15, 15.39] p = 0.05) relative to controls. There were no associations between changes in body weight, physical activity, mood, and quality of life in any group by the end of the study. These findings suggest that TRE and CR produce similar degrees of weight loss, but impact neither mood nor quality of life in adults with obesity over 12 months. Future well-powered studies will be needed to confirm these findings.

Time-Restricted Eating Without Calorie Counting for Weight Loss in a Racially Diverse Population : A Randomized Controlled Trial.

BACKGROUND: Time-restricted eating (TRE), without calorie counting, has become a popular weight loss strategy, yet long-term randomized trials evaluating its efficacy are limited. OBJECTIVE: To determine whether TRE is more effective for weight control and cardiometabolic risk reduction compared with calorie restriction (CR) or control. DESIGN: 12-month randomized controlled trial. (ClinicalTrials.gov: NCT04692532). SETTING: University of Illinois Chicago from January 2021 to September 2022. PARTICIPANTS: 90 adults with obesity. INTERVENTION: 8-hour TRE (eating between noon and 8:00 p.m. only, without calorie counting), CR (25% energy restriction daily), or control (eating over a period of 10 or more hours per day). Participants were not blinded. MEASUREMENTS: Change in body weight, metabolic markers, and energy intake by month 12. RESULTS: Seventy-seven persons completed the study. Mean age was 40 years (SD, 11), 33% were Black, and 46% were Hispanic. Mean reduction in energy intake was -425 kcal/d (SD, 531) for TRE and -405 kcal/d (SD, 712) for CR. Compared with the control group, weight loss by month 12 was -4.61 kg (95% CI, -7.37 to -1.85 kg; P ≤ 0.01) (-4.87% [CI, -7.61% to -2.13%]) for the TRE group and -5.42 kg (CI, -9.13 to -1.71 kg; P ≤ 0.01) (-5.30% [CI, -9.06% to -1.54%]) for the CR group, with no statistically significant difference between TRE and CR (0.81 kg [CI, -3.07 to 4.69 kg; P = 0.68]) (0.43% [CI, -3.48% to 4.34%]). LIMITATION: Not blinded, not powered to detect relatively large differences in weight loss, and lack of adjustment for multiple comparisons. CONCLUSION: Time-restricted eating is more effective in producing weight loss when compared with control but not more effective than CR in a racially diverse population. PRIMARY FUNDING SOURCE: National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.

Time restricted eating for the prevention of type 2 diabetes.

Type 2 diabetes can potentially be prevented by targeted lifestyle and weight loss interventions. Time restricted eating (TRE) is a form of intermittent fasting that has emerged as a novel diet strategy to reduce body weight and improve glycaemic control. TRE involves eating within a certain window of time (usually 4 to 10 h), and water-fasting for the remaining hours of the day. The purpose of this review is to summarize the effects of TRE on body weight and markers of glycaemic control in human subjects. We also aim to provide mechanistic insights into the effect of TRE on insulin sensitivity and glucose tolerance. Results to date reveal that TRE produces mild weight loss (1%-4% from baseline) and energy restriction, when food consumption is restricted to 4-10 h/day. TRE also reduces fasting insulin and improves insulin sensitivity in individuals with prediabetes and those with obesity. Moreover, TRE improves glucose tolerance and decreases serum glucose excursions. The possible mechanisms underlying these benefits include increased autophagic flux, mild elevations in ketone bodies, a reduction in oxidative stress, and the stimulation of ß-cell responsiveness. While these preliminary results offer promise for the use of TRE in the prevention of type 2 diabetes, larger and longer-term human trials will be needed to confirm these findings.

Intermittent Fasting and Sleep: A Review of Human Trials.

This review examines the effects of two popular intermittent fasting regimens on sleep in adults with overweight and obesity. Specifically, the effects of time restricted eating (TRE; eating all food within a 4-10 h window) and alternate day fasting (ADF; 600 kcal fast day alternated with ad libitum feast day) on sleep quality, sleep duration, sleep latency, sleep efficiency, insomnia severity, and risk of obstructive sleep apnea, will be summarized. The role of weight loss will also be discussed. Results from our review reveal that the majority of these trials produced weight loss in the range of 1-6% from baseline. Sleep quality and sleep duration remained unaltered with TRE and ADF, as assessed by the Pittsburgh Sleep Quality Index (PSQI). The effects of intermittent fasting on sleep latency and sleep efficiency are mixed, with one study showing worsening of these parameters, and others showing no effect. Insomnia severity and the risk of obstructive sleep apnea remained unchanged in the trials assessing these metrics. Taken together, these preliminary findings suggest that TRE and ADF produce mild to moderate weight loss (1-6%) but their effects on sleep remain unclear. Solid conclusions are difficult to establish since participants in the studies had healthy sleep durations and no clinical insomnia at baseline, leaving little room for improvement in these metrics. Moreover, none of the trials were adequately powered to detect statistically significant changes in any measure of sleep. Future well-powered trials, conducted in individuals with diagnosed sleep disturbances, will be necessary to elucidate the effect of these popular diets on sleep.