Sofia Cienfuegos

Background/Objectives: This secondary analysis aimed to compare the effects of time-restricted eating (TRE) versus calorie restriction (CR) and controls on mood and quality of life in adults with type 2 diabetes (T2D). Methods: Adults with T2D (n = 69) were randomly assigned to one of three interventions for 6 months: 8 h TRE (eating only between 12 and 8 pm daily); CR (25% energy restriction daily); or a no-intervention control group. At baseline and 6 months, mood was assessed using the Beck Depression Inventory-II (BDI-II) and the Profile of Mood States (POMS) questionnaires, while quality of life was assessed using the Rand 36-Item Short Form (SF-36). Results: Body weight significantly decreased in the TRE group (−3.38%; 95% CI, −6.04 to −0.71%, p = 0.008), but not in the CR group (−1.80%, 95% CI, −4.50 to 0.91%, p = 0.32) versus controls by month 6. Fat mass, lean mass, and visceral fat mass remained unchanged in TRE and CR groups, versus controls, from baseline to month 6. No changes were observed in depression scores (BDI-II), total mood disturbance, or any POMS subscales (tension, depression, anger, fatigue, confusion, or vigor) in either the TRE or CR groups compared to controls. Similarly, there were no significant changes in the quality-of-life SF-36 constructs of vitality, bodily pain, mental health, and general physical health in the TRE or CR group versus controls. By month 6, there were no associations between changes in body weight, quality of life, and mood outcomes in any group. Conclusions: In conclusion, our findings suggest that TRE and CR do not have any effect on mood or quality of life in adults with T2D, relative to controls. However, the participants’ baseline mood and quality of life were generally within healthy ranges, and only minimal weight loss was achieved (3.5%, TRE only), which may explain the lack of observed effects.

Background/Objectives: Obesity is associated with chronic systemic inflammation and elevated levels of inflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein (CRP). Weight loss through lifestyle interventions can reduce inflammation in adults with obesity. Time-restricted eating (TRE) and calorie restriction (CR) are two popular diet interventions that can produce clinically significant weight loss. However, to date, no studies have directly compared the effects of TRE versus CR on inflammatory cytokines in adults with obesity. Methods: Here, we performed a secondary analysis on a recently published study to compare the long-term (12-month) effects of TRE versus CR on key inflammatory cytokines. Results: We found that while TRE and CR produced similar amounts of weight loss (4–5% from baseline), no statistically significant changes in circulating levels of TNF-alpha, IL-6, and CRP were noted in the TRE or CR groups, compared to the controls, by month 12. However, we did observe that circulating CRP levels were positively related to body weight, visceral fat mass, and insulin resistance, while IL-6 and TNF-alpha were not related to any metabolic marker. Conclusions: Thus, TRE and CR may not affect key inflammatory mediators with 4–5% weight loss, but more research is warranted.

Objective: The aim of this secondary analysis was to compare the effects of time-restricted eating (TRE) versus daily calorie restriction (CR) on sleep quality, duration, insomnia severity, and risk of obstructive sleep apnea in adults with obesity over one year. Methods: A total of 90 participants were randomized to one of three groups for 12 months: 8 h TRE (eating only between 12 p.m. and 8 p.m.); CR (25% daily calorie restriction) or a no-intervention control group. Results: By the end of the study, weight loss was 4.61 kg (95% CI; 7.37 to 1.85 kg; p ≤ 0.01) for the TRE group and 5.42 kg (CI; 9.13 to 1.71 kg; p ≤ 0.01) for the CR group, with no statistically significant difference between TRE and CR (0.81 kg [CI; 3.07 to 4.69]; p = 0.68]). Self-reported sleep quality, sleep duration, insomnia severity, and risk of obstructive sleep apnea did not change in the TRE or CR groups versus controls by month 12. Conclusions: These findings suggest that the weight loss produced by TRE and CR does not have any impact on various sleep parameters in adults with obesity over one year.

Obesity is associated with alterations in circulating IGF1, IGF1-binding proteins (IGFBPs), insulin, inflammatory markers, and hormones implicated in cardiovascular disease, diabetes, cancer, and aging. However, the effects of 4 and 6 h time-restricted eating (TRE) on circulating IGF1 and IGFBPs is uncertain. Objective: This study aimed to investigate the effects of TRE on plasma IGF1, IGFBP1, IGFBP2, and IGFBP3, and whether these effects were mediated by weight loss or body composition changes. Insulin sensitivity, glucose control, adipokines, and inflammatory markers were also examined. Design: An exploratory analysis of an 8-week randomized controlled trial implementing a daily TRE intervention was carried out. Participants/Setting: This study was conducted at the University of Illinois at Chicago in 2019. Participants with obesity were randomized to 4 or 6 h TRE (n = 35) or a control (n = 14) group. Plasma biomarkers were measured by ELISA at baseline and week 8. In a sub-analysis, participants were stratified into higher- (>3.5%) and lower- (≤3.5%) weight-loss groups. Intervention: Participants fasted daily from 7 p.m. to 3 p.m. in the 4 h TRE group (20 h) and from 7 p.m. to 1 p.m. in the 6 h TRE group (18 h), followed by ad libitum eating for the remainder of the day. Controls received no dietary recommendations. Main outcome measures: IGF1, IGFBPs, hsCRP, and adipokines were the main outcome measures of this analysis. Statistical Analysis: Repeated measures ANOVA and mediation analysis were conducted. Results: Body weight significantly decreased with TRE (−3.6 ± 0.3%), contrasting with controls (+0.2 ± 0.5%, p < 0.001). Significant effects of TRE over time were observed on plasma IGFBP2, insulin, HOMA-IR, and 8-isoprostane levels, without affecting other biomarkers. In the sub-analysis, IGFBP2 increased while leptin and 8-isoprostane decreased significantly only in the “higher weight loss” subgroup. Changes in insulin and HOMA-IR were related to TRE adherence. Conclusions: Eight-week daily 4 to 6 h TRE did not affect IGF1, IGFBP1, or IGFBP3 levels but improved insulin, HOMA-IR, and 8-isoprostane. IGFBP2 increased and leptin decreased when weight loss exceeded 3.5% of baseline.

The aim of this secondary analysis was to compare the effects of time-restricted eating (TRE) versus calorie restriction (CR) and controls on sleep in adults with type 2 diabetes (T2D). Adults with T2D (n = 75) were randomized to 1 of 3 interventions for 6 months: 8 h TRE (eating only between 12 and 8 pm daily); CR (25% energy restriction daily); or control. Our results show that TRE has no effect on sleep quality, duration, insomnia severity, or risk of obstructive sleep apnea, relative to CR and controls, in patients with T2D over 6 months.

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.

Objective: This study investigated how alternate-day fasting (ADF) combined with aerobic exercise impacts body weight and sleep in adults with non-alcoholic fatty liver disease (NAFLD). Methods: Adults with obesity and NAFLD (n = 80) were randomized into one of four groups for 3 months: combination of ADF (600 kcal “fast day,” alternated with an ad libitum intake “feast day”) and moderate-intensity aerobic exercise (five sessions per week, 60 min/session); ADF alone; exercise alone; or a no-intervention control group. Results: By month 3, body weight and intrahepatic triglyceride content decreased (p < 0.001, group × time interaction) in the combination group versus the exercise group and control group, but not versus the ADF group. Sleep quality, measured by the Pittsburgh Sleep Quality Inventory (PSQI), did not change in the combination group (baseline: 6.0 ± 0.7; month 3: 5.6 ± 0.7), ADF group (baseline: 8.9 ± 1.0; month 3: 7.5 ± 0.8), or exercise group (baseline: 6.4 ± 0.6; month 3: 6.7 ± 0.6), versus controls (baseline: 5.5 ± 0.7; month 3: 4.6 ± 0.5). Wake time, bedtime, sleep duration, and insomnia severity did not change (no group x time interaction) over the course of the study in any group. Risk for obstructive sleep apnea was present in 30% of combination subjects, 75% of ADF subjects, 40% of exercise subjects, and 75% of controls, and did not change in the intervention groups, versus controls, by month 3. No associations were observed between changes in body weight, intrahepatic triglyceride content, and any sleep outcome. Conclusions: The weight loss induced by ADF combined with exercise does not improve sleep quality, duration, insomnia severity, or risk of obstructive sleep apnea in individuals with NAFLD.

Intermittent fasting is a popular diet for weight loss, but concerns have been raised regarding the effects of fasting on the reproductive health of women and men. Accordingly, we conducted this literature review to clarify the effects of fasting on reproductive hormone levels in humans. Our results suggest that intermittent fasting decreases androgen markers (i.e., testosterone and the free androgen index (FAI)) while increasing sex hormone-binding globulin (SHBG) levels in premenopausal females with obesity. This effect was more likely to occur when food consumption was confined to earlier in the day (eating all food before 4 pm). In contrast, fasting did not have any effect on estrogen, gonadotropins, or prolactin levels in women. As for men, intermittent fasting reduced testosterone levels in lean, physically active, young males, but it did not affect SHBG concentrations. Interestingly, muscle mass and muscular strength were not negatively affected by these reductions in testosterone. In interpreting these findings, it is important to note that very few studies have been conducted on this topic. Thus, it is difficult to draw solid conclusions at present. From the limited data presented here, it is possible that intermittent fasting may decrease androgen markers in both genders. If this is the case, these results would have varied health implications. On the one hand, fasting may prove to be a valuable tool for treating hyperandrogenism in females with polycystic ovarian syndrome (PCOS) by improving menstruation and fertility. On the other hand, fasting may be shown to decrease androgens among males, which could negatively affect metabolic health and libido. More research is warranted to confirm these preliminary findings.

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.

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 β‐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. image