"It gave me a sense of achievement and a sense of purpose"-a qualitative study of patient experiences of a virtually supervised exercise program for adults with advanced cancer and cachexia.

People with advanced cancer and cachexia experience significant body weight loss, adversely impacting physical function and quality of life (QOL). Effective, evidence-based treatments for cancer cachexia are lacking, leaving patients with unmet needs. Exercise holds promise to improve patient QOL. However, information on patients' experiences of exercise, including their ability to cope with structured exercise, is limited. PURPOSE: To explore patient experiences completing a structured, supervised exercise program for people with cachexia due to advanced cancer. METHODS: Semi-structured interviews were conducted with participants enrolled in a phase II feasibility, randomized controlled trial to explore their experiences of an 8-week virtually supervised exercise program delivered via videoconference technology. Interviews were analysed using reflexive thematic analysis. RESULTS: Seventeen participants completed interviews (female n = 9, 53%). Main interview themes included the following: (1) Deciding to exercise involves balancing concerns and expectations, (2) the exercise program is a positive experience, and (3) moving forward after the exercise program. While some participants initially held doubts about their physical capabilities and exercise safety, most wanted to exercise to enhance their wellbeing. Participants described the exercise program as a positive experience, offering diverse benefits. Some would have preferred in-person exercise, but all agreed the virtual format increased convenience. Participants emphasized the need to recommend the program to others in similar circumstances. They underscored the necessity and desire for ongoing support to sustain their new exercise habits. CONCLUSION: Based on patient experiences, virtually supervised exercise programming appears to be feasible and meaningful to people with advanced cancer and cachexia.

Exploring Australian Dietitians' knowledge, experience and perspectives of time-restricted eating in private practice: A qualitative study.

Time-restricted eating is a novel nutrition intervention with evidence of beneficial effects on weight loss, blood glucose management, and other metabolic health outcomes. Adherence to time-restricted eating is higher than some traditional nutrition interventions to support individuals living with overweight/obesity and type 2 diabetes mellitus. However, there may be an evidence-practice gap of time-restricted eating in Australian dietetic practice. The present study aimed to explore dietitians' knowledge, experiences, and perspectives of time-restricted eating and timing of eating advice in practice. Semi-structured interviews with 10 private practice dietitians across Australia were conducted. Audio recordings were transcribed and analysed thematically. Six themes were identified: (i) distinction of time-restricted eating to other fasting protocols; (ii) knowledge of health benefits of time-restricted eating; (iii) patient-led advice frequently given: timing of breakfast and dinner; (iv) dietitian-led advice frequently given: eating cut-off time to avoid late night snacking; (v) barriers and facilitators to offering time-restricted eating or timing of eating advice; (vi) timing of eating advice within professional guidelines and resources. These findings suggest the need for development of professional resources and educational development tools for dietitians on time-restricted eating.

Combined effects of exercise and different levels of acute hypoxic severity: A randomized crossover study on glucose regulation in adults with overweight.

Purpose: The aim of this study was to investigate the influence of manipulating hypoxic severity with low-intensity exercise on glucose regulation in healthy overweight adults. Methods: In a randomized crossover design, 14 males with overweight (age: 27 ± 5 years; body mass index (BMI) 27.1 ± 1.8 kg⋅m2) completed three exercise trials involving 60 min aerobic exercise cycling at 90% lactate threshold in normoxia (NM, FiO2 = 20.9%), moderate hypoxia (MH, FiO2 = 16.5%) and high hypoxia (HH, FiO2 = 14.8%). A post-exercise oral glucose tolerance test (OGTT) was performed. Venous blood samples were analyzed for incremental area under the curve (iAUC), plasma glucose and insulin, as well as exerkine concentrations (plasma apelin and fibroblast growth factor 21 [FGF-21]) pre- and post-exercise. A 24-h continuous glucose monitoring (CGM) was used to determine interstitial glucose concentrations. Heart rate, oxygen saturation (SpO2) and perceptual measures were recorded during exercise. Results: Post-exercise OGTT iAUC for plasma glucose and insulin concentrations were lower in MH vs. control (p = 0.02). Post-exercise interstitial glucose iAUC, plasma apelin and FGF-21 were not different between conditions. Heart rate was higher in HH vs. NM and MH, and MH vs. NM (p < 0.001), while SpO2 was lower in HH vs. NM and MH, and MH vs. NM (p < 0.001). Overall perceived discomfort and leg discomfort were higher in HH vs. NM and MH (p < 0.05), while perceived breathing difficulty was higher in HH vs. NM only (p = 0.003). Conclusion: Compared to higher hypoxic conditions, performing acute aerobic-based exercise under moderate hypoxia provided a more effective stimulus for improving post-exercise glucose regulation while concomitantly preventing excessive physiological and perceptual stress in healthy overweight adults.

Effect of high-fat diet and morning or evening exercise on lipoprotein subfraction profiles: secondary analysis of a randomised trial.

We investigated the effect of a high-fat diet (HFD) on serum lipid subfractions in men with overweight/obesity and determined whether morning or evening exercise affected these lipid profiles. In a three-armed randomised trial, 24 men consumed an HFD for 11 days. One group of participants did not exercise (n = 8, CONTROL), one group trained at 06:30 h (n = 8, EXam), and one group at 18:30 h (n = 8, EXpm) on days 6-10. We assessed the effects of HFD and exercise training on circulating lipoprotein subclass profiles using NMR spectroscopy. Five days of HFD induced substantial perturbations in fasting lipid subfraction profiles, with changes in 31/100 subfraction variables (adjusted p values [q] < 0.05). Exercise training induced a systematic change in lipid subfraction profiles, with little overall difference between EXam and EXpm. Compared with CONTROL, exercise training reduced serum concentrations of > 20% of fasting lipid subfractions. EXpm reduced fasting cholesterol concentrations in three LDL subfractions by ⁓30%, while EXam only reduced concentration in the largest LDL particles by 19% (all q < 0.05). Lipid subfraction profiles changed markedly after 5 days HFD in men with overweight/obesity. Both morning and evening exercise training impacted subfraction profiles compared with no exercise.

Time-restricted eating improves measures of daily glycaemic control in people with type 2 diabetes.

AIMS: Examine the effect of 5 d/wk, 9-h time-restricted eating (TRE) protocol on 24-h glycaemic control in adults with type 2 diabetes (T2D). METHODS: Nineteen adults with T2D (10 F/9 M; 50 ± 9 y, HbA1c 7.6% (60 mmol/mol), BMI ∼34 kg/m2) completed a pre-post non-randomised trial comprising of a 2-wk Habitual monitoring period followed by 9-h (10:00-19:00 h) TRE for 4-wk. Glycaemic control was assessed via continuous glucose monitoring (CGM; for mean 24-h glucose concentrations, 24-h total area under the curve (AUC) and glucose variability metrics), with dietary records and physical activity monitoring. Changes in CGM measures, dietary intake and physical activity were assessed with linear mixed-effects models. RESULTS: TRE did not alter dietary energy intake, macronutrient composition or physical activity, but reduced the daily eating window (-2 h 35 min, P < 0.001). Compared to the Habitual period, 24-h glucose concentrations (mean, SD) and AUC decreased in the 4-wk TRE period (mean: -0.7 ± 1.2 mmol/L, P = 0.02; SD: -0.2 ± 0.3 mmol/L, P = 0.01; 24-h AUC: -0.9 ± 1.4 mmol/L⋅h-1 P = 0.01). During TRE, participants spent 10% more time in range (3.9-10.0 mmol/L; P = 0.02) and 10% less time above range (>10.0 mmol/L; P = 0.02). CONCLUSIONS: Adhering 5 d/wk. to 9-h TRE improved glycaemic control in adults with T2D, independent of changes in physical activity or dietary intake. CLINICAL TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry, ACTRN12618000938202.

Eight-hour time-restricted eating does not lower daily myofibrillar protein synthesis rates: A randomized control trial.

OBJECTIVE: This study aimed to assess the impact of time-restricted eating (TRE) on integrated skeletal muscle myofibrillar protein synthesis (MyoPS) rates in males with overweight/obesity. METHODS: A total of 18 healthy males (age 46 ± 5 years; BMI: 30 ± 2 kg/m2 ) completed this exploratory, parallel, randomized dietary intervention after a 3-day lead-in diet. Participants then consumed an isoenergetic diet (protein: ~1.0 g/kg body mass per day) following either TRE (10:00 a.m. to 6:00 p.m.) or an extended eating control (CON; 8:00 a.m. to 8:00 p.m.) protocol for 10 days. Integrated MyoPS rates were measured using deuterated water administration with repeated saliva, blood, and muscle sampling. Secondary measures included continuous glucose monitoring and body composition (dual-energy x-ray absorptiometry). RESULTS: There were no differences in daily integrated MyoPS rates (TRE: 1.28% ± 0.18% per day, CON: 1.26% ± 0.22% per day; p = 0.82) between groups. From continuous glucose monitoring, 24-hour total area under the curve was reduced following TRE (-578 ± 271 vs. CON: 12 ± 272 mmol/L × 24 hours; p = 0.001). Total body mass declined (TRE: -1.6 ± 0.9 and CON: -1.1 ± 0.7 kg; p < 0.001) with no differences between groups (p = 0.22). Lean mass loss was greater following TRE compared with CON (-1.0 ± 0.7 vs. -0.2 ± 0.5 kg, respectively; p = 0.01). CONCLUSION: Consuming food within an 8-hour time-restricted period does not lower daily MyoPS rates when compared with an isoenergetic diet consumed over 12 hours. Future research should investigate whether these results translate to free-living TRE.

Cardiometabolic health impacts of time-restricted eating: implications for type 2 diabetes, cancer and cardiovascular diseases.

PURPOSE OF REVIEW: Time-restricted eating (TRE) entails consuming energy intake within a 4- to 10-h window, with the remaining time spent fasting. Although studies have reported health benefits from TRE, little is known about the impact of TRE on common chronic diseases such as type 2 diabetes, cancer and cardiovascular disease. This review summarizes and critically evaluates the most recent TRE research findings relevant to managing and treating these chronic diseases. RECENT FINDINGS: Most recent TRE studies have been in populations with overweight/obesity or metabolic syndrome; two have been in populations with diabetes, three in cancer survivors and none in populations with cardiovascular disease. Collectively, these studies showed that participants could adhere to TRE and TRE is well tolerated. These studies also showed preliminary efficacy for improved glucose regulation and insulin sensitivity, a reduction in body fat and blood pressure, reduced cardiovascular risk scores and increased quality of life. More research is required to define the most effective TRE protocol (i.e. length and timing of eating window, intervention duration). SUMMARY: TRE has demonstrated benefits on cardiovascular, metabolic and clinical outcomes relevant to the underlying pathophysiology, but there are limited data on TRE implemented specifically within populations with diabetes, cancer or cardiovascular disease.

"I want to get myself as fit as I can and not die just yet" - Perceptions of exercise in people with advanced cancer and cachexia: a qualitative study.

Cachexia is a prevalent muscle wasting syndrome among people with advanced cancer that profoundly impacts patient quality of life (QoL) and physical function. Exercise can improve QoL, physical function, and overall health in people with cancer and may be an important addition to treatment approaches for cancer cachexia. Greater understanding of patients' perception of exercise can help elucidate the feasibility of implementing exercise interventions for cancer cachexia and facilitate the design of patient-centered interventions. We aimed to describe the perception of exercise in patients with advanced cancer and cachexia, and capture exercise motivators, barriers, and preferences, to inform the feasibility of exercise interventions. Individual interviews (n = 20) with patients with locally advanced or metastatic cancer with cachexia were conducted and analyzed using reflexive thematic analysis. Main themes from interviews were: 1) Life is disrupted by cancer and cachexia; 2) Exercise offers hope; 3) Exercise barriers are multifaceted; and 4) Exercise access and support are important. Participants reported that their cancer and cachexia had intensely altered their lives, including ability to exercise. Exercise was perceived as important and participants described a hope for exercise to improve their health and wellbeing. Yet, several complex exercise barriers, such as burdensome cancer symptoms and the overwhelming impact of the COVID-19 pandemic, hindered exercise participation and prevented participants from fully realizing the perceived benefits of exercise. Factors believed to improve exercise engagement and overcome exercise barriers included increased exercise support (e.g., professional supervision) and accessibility (e.g., convenient locations). Patient-reported exercise barriers and preferences can inform the design of exercise interventions, particularly within future research studies aiming to establish exercise feasibility and efficacy in people with advanced cancer and cachexia.

Perspective: Time-Restricted Eating-Integrating the What with the When.

Time-restricted eating (TRE) is a popular dietary strategy that emphasizes the timing of meals in alignment with diurnal circadian rhythms, permitting ad libitum energy intake during a restricted (∼8-10 h) eating window each day. Unlike energy-restricted diets or intermittent fasting interventions that focus on weight loss, many of the health-related benefits of TRE are independent of reductions in body weight. However, TRE research to date has largely ignored what food is consumed (i.e., macronutrient composition and energy density), overlooking a plethora of past epidemiological and interventional dietary research. To determine some of the potential mechanisms underpinning the benefits of TRE on metabolic health, future studies need to increase the rigor of dietary data collected, assessed, and reported to ensure a consistent and standardized approach in TRE research. This Perspective article provides an overview of studies investigating TRE interventions in humans and considers dietary intake (both what and when food is eaten) and their impact on selected health outcomes (i.e., weight loss, glycemic control). Integrating existing dietary knowledge about what food is eaten with our recent understanding on when food should be consumed is essential to optimize the impact of dietary strategies aimed at improving metabolic health outcomes.

High-Intensity Interval Training in Polycystic Ovary Syndrome: A Two-Center, Three-Armed Randomized Controlled Trial.

PURPOSE: Exercise training is recommended to improve cardiometabolic health and fertility in women with polycystic ovary syndrome (PCOS), yet there are few randomized controlled trials on the effects of different exercise protocols on clinical reproductive outcomes. Our aim was to determine the effect of high-intensity interval training (HIT) on menstrual frequency, as a proxy of reproductive function, in women with PCOS. METHODS: The IMPROV-IT study was a two-center randomized controlled trial undertaken in Norway and Australia. Women with PCOS were eligible for inclusion. After stratification for body mass index <27 or ≥27 kg·m-2 and study center, participants were randomly allocated (1:1:1) to high-volume HIT (HV-HIT), low-volume HIT (LV-HIT), or a control group. Measurements were assessed at baseline, after the 16-wk exercise intervention, and at 12-month follow-up. The primary outcome was menstrual frequency after 12 months. Secondary outcomes included markers of cardiometabolic and reproductive health, quality of life, and adherence to and enjoyment of HIT. RESULTS: We randomly allocated 64 participants to the HV-HIT (n = 20), LV-HIT (n = 21), or control group (n = 23). There were no differences in menstrual frequency at 12 months between the LV-HIT and control groups (frequency ratio, 1.02; 95% confidence interval [CI], 0.73-1.42), the HV-HIT and control groups (frequency ratio, 0.93; 95% CI, 0.67-1.29), or the LV-HIT and HV-HIT groups (frequency ratio, 1.09; 95% CI, 0.77-1.56). Menstrual frequency increased in all groups from baseline to 12 months. More participants became pregnant in the LV-HIT group (n = 5) than in the control group (n = 0, P = 0.02). CONCLUSIONS: A semisupervised HIT intervention did not increase menstrual frequency in women with PCOS.Clinical Trial Registration Number:ClinicalTrials.gov (NCT02419482).

The effect of morning vs evening exercise training on glycaemic control and serum metabolites in overweight/obese men: a randomised trial.

AIMS/HYPOTHESIS: We determined whether the time of day of exercise training (morning vs evening) would modulate the effects of consumption of a high-fat diet (HFD) on glycaemic control, whole-body health markers and serum metabolomics. METHODS: In this three-armed parallel-group randomised trial undertaken at a university in Melbourne, Australia, overweight/obese men consumed an HFD (65% of energy from fat) for 11 consecutive days. Participants were recruited via social media and community advertisements. Eligibility criteria for participation were male sex, age 30-45 years, BMI 27.0-35.0 kg/m2 and sedentary lifestyle. The main exclusion criteria were known CVD or type 2 diabetes, taking prescription medications, and shift-work. After 5 days, participants were allocated using a computer random generator to either exercise in the morning (06:30 hours), exercise in the evening (18:30 hours) or no exercise for the subsequent 5 days. Participants and researchers were not blinded to group assignment. Changes in serum metabolites, circulating lipids, cardiorespiratory fitness, BP, and glycaemic control (from continuous glucose monitoring) were compared between groups. RESULTS: Twenty-five participants were randomised (morning exercise n = 9; evening exercise n = 8; no exercise n = 8) and 24 participants completed the study and were included in analyses (n = 8 per group). Five days of HFD induced marked perturbations in serum metabolites related to lipid and amino acid metabolism. Exercise training had a smaller impact than the HFD on changes in circulating metabolites, and only exercise undertaken in the evening was able to partly reverse some of the HFD-induced changes in metabolomic profiles. Twenty-four-hour glucose concentrations were lower after 5 days of HFD compared with the participants' habitual diet (5.3 ± 0.4 vs 5.6 ± 0.4 mmol/l, p = 0.001). There were no significant changes in 24 h glucose concentrations for either exercise group but lower nocturnal glucose levels were observed in participants who trained in the evening, compared with when they consumed the HFD alone (4.9 ± 0.4 vs 5.3 ± 0.3 mmol/l, p = 0.04). Compared with the no-exercise group, peak oxygen uptake improved after both morning (estimated effect 1.3 ml min-1 kg-1 [95% CI 0.5, 2.0], p = 0.003) and evening exercise (estimated effect 1.4 ml min-1 kg-1 [95% CI 0.6, 2.2], p = 0.001). Fasting blood glucose, insulin, cholesterol, triacylglycerol and LDL-cholesterol concentrations decreased only in participants allocated to evening exercise training. There were no unintended or adverse effects. CONCLUSIONS/INTERPRETATION: A short-term HFD in overweight/obese men induced substantial alterations in lipid- and amino acid-related serum metabolites. Improvements in cardiorespiratory fitness were similar regardless of the time of day of exercise training. However, improvements in glycaemic control and partial reversal of HFD-induced changes in metabolic profiles were only observed when participants exercise trained in the evening. TRIAL REGISTRATION: anzctr.org.au registration no. ACTRN12617000304336. FUNDING: This study was funded by the Novo Nordisk Foundation (NNF14OC0011493).

Skeletal Muscle Adaptive Responses to Different Types of Short-Term Exercise Training and Detraining in Middle-Age Men.

INTRODUCTION: Whether short-term, single-mode exercise training can improve physical fitness before a period of reduced physical activity (e.g., postsurgery recovery) is not well characterized in clinical populations or middle-age adults. We investigated skeletal muscle adaptive responses after endurance exercise training (ENT), high-intensity interval training (HIIT), or resistance exercise training (RET), and a subsequent period of detraining, in sedentary, middle-age men. METHODS: Thirty-five sedentary men (39 ± 3 yr) were randomized to parallel groups and undertook 6 wk of either ENT (n = 12), HIIT (n = 12), or RET (n = 11) followed by 2.5 wk of detraining. Skeletal muscle fiber characteristics, body composition, muscle thickness, muscle strength, aerobic capacity, resting energy expenditure, and glucose homeostasis were assessed at baseline, and after exercise training and detraining. RESULTS: Lean mass increased after RET and HIIT (+3.2% ± 1.6% and +1.6% ± 2.1%, P < 0.05). Muscle strength (sum of leg press, leg extension, and bench press one-repetition maximums) increased after all training interventions (RET, +25% ± 5%; HIIT, +10% ± 5%; ENT, +7% ± 7%; P < 0.05). Aerobic capacity increased only after HIIT and ENT (+14% ± 7% and +11% ± 11%, P < 0.05). Type I and II muscle fiber size increased for all groups after training (main effect of time, P < 0.05). After a period of detraining, the gains in lean mass and maximal muscle strength were maintained in the RET and HIIT groups, but maximal aerobic capacity declined below posttraining levels in HIIT and ENT (P < 0.05). CONCLUSIONS: Six weeks of HIIT induced widespread adaptations before detraining in middle-age men. Exercise training-induced increases in aerobic capacity declined during 2.5 wk of detraining, but gains in lean mass and muscle strength were maintained.

Can High-Intensity Interval Training Promote Skeletal Muscle Anabolism?

Exercise training in combination with optimal nutritional support is an effective strategy to maintain or increase skeletal muscle mass. A single bout of resistance exercise undertaken with adequate protein availability increases rates of muscle protein synthesis and, when repeated over weeks and months, leads to increased muscle fiber size. While resistance-based training is considered the 'gold standard' for promoting muscle hypertrophy, other modes of exercise may be able to promote gains in muscle mass. High-intensity interval training (HIIT) comprises short bouts of exercise at or above the power output/speed that elicits individual maximal aerobic capacity, placing high tensile stress on skeletal muscle, and somewhat resembling the demands of resistance exercise. While HIIT induces rapid increases in skeletal muscle oxidative capacity, the anabolic potential of HIIT for promoting concurrent gains in muscle mass and cardiorespiratory fitness has received less scientific inquiry. In this review, we discuss studies that have determined muscle growth responses after HIIT, with a focus on molecular responses, that provide a rationale for HIIT to be implemented among populations who are susceptible to muscle loss (e.g. middle-aged or older adults) and/or in clinical settings (e.g. pre- or post-surgery).

Lower nocturnal blood glucose response to a potato-based mixed evening meal compared to rice in individuals with type 2 diabetes.

BACKGROUND & AIMS: Guidelines for reducing postprandial blood glucose concentrations include avoiding high glycemic index (GI) foods, such as white potatoes. However, GI testing is often undertaken in the morning with foods consumed in isolation by non-clinical cohorts. We investigated the impact of potato preparation and consumption as part of a mixed-evening meal on postprandial and nocturnal glycemic responses, and postprandial insulin response, in individuals with Type 2 Diabetes Mellitus (T2DM). METHODS: In a randomized, cross-over design, 24 males and females (age 58.3 ± 9.3 y; BMI: 31.7 ± 6.8 kg/m2) with T2DM (diet or metformin controlled) completed four experimental trials after consuming a standardized breakfast (25% daily energy intake (EI)) and lunch (35% EI). Dinner (40% EI) was consumed at 1800 h being either: 1) boiled potato (BOIL); 2) roasted potato (ROAST); 3) boiled potato cooled for 24 h (COOLED); or 4) basmati rice (CONTROL). Each meal contained 50% carbohydrate, 30% fat and 20% protein. Blood samples were collected prior to, immediately post meal and at 30-min intervals for a further 120 min. A continuous glucose monitor was worn to assess nocturnal interstitial glucose concentrations. RESULTS: No differences were detected in postprandial venous glucose area under the curve (iAUC) between CONTROL and all three potato conditions. Postprandial insulin iAUC was greater following COOLED compared to CONTROL (P = 0.003; 95% CI: 18.9-111.72 miU/mL). No significant differences between CONTROL and BOIL or ROAST were detected for postprandial insulin concentrations. All potato meals resulted in lower nocturnal glucose AUC than CONTROL (P < 0.001; 95% CI 4.15-15.67 mmol/L x h). CONCLUSION: Compared to an isoenergetic rice meal, boiled, roasted or boiled then cooled potato-based meals were not associated with unfavourable postprandial glucose responses or nocturnal glycemic control, and can be considered suitable for individuals with T2DM when consumed as part of a mixed-evening meal. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry https://www.anzctr.org.au/, ACTRN 12618000480280.

Time-Restricted Eating as a Nutrition Strategy for Individuals with Type 2 Diabetes: A Feasibility Study.

Individuals with type 2 diabetes (T2D) require a long-term dietary strategy for blood glucose management and may benefit from time-restricted eating (TRE, where the duration between the first and last energy intake is restricted to 8-10 h/day). We aimed to determine the feasibility of TRE for individuals with T2D. Participants with T2D (HbA1c >6.5 to <9%, eating window >12 h/day) were recruited to a pre-post, non-randomised intervention consisting of a 2-week Habitual period to establish baseline dietary intake, followed by a 4-weeks TRE intervention during which they were instructed to limit all eating occasions to between 10:00 and 19:00 h on as many days of each week as possible. Recruitment, retention, acceptability, and safety were recorded throughout the study as indicators of feasibility. Dietary intake, glycaemic control, psychological well-being, acceptability, cognitive outcomes, and physiological measures were explored as secondary outcomes. From 594 interested persons, and 27 eligible individuals, 24 participants enrolled and 19 participants (mean ± SD; age: 50 ± 9 years, BMI: 34 ± 5 kg/m2, HbA1c: 7.6 ± 1.1%) completed the 6-week study. Overall daily dietary intake did not change between Habitual (~8400 kJ/d; 35% carbohydrate, 20% protein, 41% fat, 1% alcohol) and TRE periods (~8500 kJ/d; 35% carbohydrate, 19% protein, 42% fat, 1% alcohol). Compliance to the 9 h TRE period was 72 ± 24% of 28 days (i.e., ~5 days/week), with varied adherence (range: 4-100%). Comparisons of adherent vs. non-adherent TRE days showed that adherence to the 9-h TRE window reduced daily energy intake through lower absolute carbohydrate and alcohol intakes. Overall, TRE did not significantly improve measures of glycaemic control (HbA1c -0.2 ± 0.4%; p = 0.053) or reduce body mass. TRE did not impair or improve psychological well-being, with variable effects on cognitive function. Participants described hunger, daily stressors, and emotions as the main barriers to adherence. We demonstrate that 4-weeks of TRE is feasible and achievable for these individuals with T2D to adhere to for at least 5 days/week. The degree of adherence to TRE strongly influenced daily energy intake. Future trials may benefit from supporting participants to incorporate TRE in regular daily life and to overcome barriers to adherence.

Author Correction: Time-restricted feeding alters lipid and amino acid metabolite rhythmicity without perturbing clock gene expression.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Time-restricted feeding alters lipid and amino acid metabolite rhythmicity without perturbing clock gene expression.

Time-restricted feeding (TRF) improves metabolism independent of dietary macronutrient composition or energy restriction. To elucidate mechanisms underpinning the effects of short-term TRF, we investigated skeletal muscle and serum metabolic and transcriptomic profiles from 11 men with overweight/obesity after TRF (8 h day-1) and extended feeding (EXF, 15 h day-1) in a randomised cross-over design (trial registration: ACTRN12617000165381). Here we show that muscle core clock gene expression was similar after both interventions. TRF increases the amplitude of oscillating muscle transcripts, but not muscle or serum metabolites. In muscle, TRF induces rhythmicity of several amino acid transporter genes and metabolites. In serum, lipids are the largest class of periodic metabolites, while the majority of phase-shifted metabolites are amino acid related. In conclusion, short-term TRF in overweight men affects the rhythmicity of serum and muscle metabolites and regulates the rhythmicity of genes controlling amino acid transport, without perturbing core clock gene expression.

Circulating and Adipose Tissue miRNAs in Women With Polycystic Ovary Syndrome and Responses to High-Intensity Interval Training.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally. In women with polycystic ovary syndrome (PCOS), several miRNAs are differentially expressed compared to women without PCOS, suggesting a role for miRNAs in PCOS pathophysiology. Exercise training modulates miRNA abundance and is primary lifestyle intervention for women with PCOS. Accordingly, we measured the expression of eight circulating miRNAs selected a priori along with miRNA expression from gluteal and abdominal adipose tissue (AT) in 12 women with PCOS and 12 women matched for age and body mass index without PCOS. We also determined the miRNA expression "signatures" before and after high-intensity interval training (HIT) in 42 women with PCOS randomized to either: (1) low-volume HIT (LV-HIT, 10 × 1 min work bouts at maximal, sustainable intensity, n = 13); (2) high-volume HIT (HV-HIT, 4 × 4 min work bouts reaching 90-95% of maximal heart rate, n = 14); or (3) non-exercise control (Non-Ex, n = 15). Both HIT groups trained three times/week for 16 weeks. miRNAs were extracted from plasma, gluteal and abdominal AT, and quantified via a customized plate array containing eight miRNAs associated with PCOS and/or exercise training responses. Basal expression of circulating miRNA-27b (c-miR-27b), implicated in fatty acid metabolism, adipocyte differentiation and inflammation, was 1.8-fold higher in women with compared to without PCOS (P = 0.006) despite no difference in gluteal or abdominal AT miR-27b expression. Only the HV-HIT protocol increased peak oxygen uptake (VO2peak L/min; 9%, P = 0.008). There were no changes in body composition. In LV-HIT, but not HV-HIT, the expression of c-miR-27b decreased (0.5-fold, P = 0.007). None of the remaining seven circulating miRNAs changed in LV-HIT, nor was the expression of gluteal or abdominal AT miRNAs altered. Despite increased cardiorespiratory fitness, HV-HIT did not alter the expression of any circulating, gluteal or abdominal AT miRNAs. We conclude that women with PCOS have a higher basal expression of c-miR-27b compared to women without PCOS and that 16 weeks of LV-HIT reduces the expression of this miRNA in women with PCOS. Intense exercise training had little effect on the abundance of the selected miRNAs within subcutaneous AT depots in women with PCOS.

A Delayed Morning and Earlier Evening Time-Restricted Feeding Protocol for Improving Glycemic Control and Dietary Adherence in Men with Overweight/Obesity: A Randomized Controlled Trial.

We determined the effects of time-restricted feeding (TRF; 8 h/d) versus extended feeding (EXF; 15 h/d) on 24-h and postprandial metabolism and subjective opinions of TRF in men with overweight/obesity. In a randomized crossover design, 11 sedentary males (age 38 ± 5 y; BMI: 32.2 ± 2.0 kg/m2) completed two isoenergetic diet protocols for 5 days, consuming meals at 1000, 1300 and 1700 h (TRF) or 0700, 1400 and 2100 h (EXF). On Day 5, participants remained in the laboratory for 24 h, and blood samples were collected at hourly (0700-2300 h) then 2-hourly (2300-0700 h) intervals for concentrations of glucose, insulin and appetite/incretin hormones. Structured qualitative interviews were conducted following completion of both dietary conditions and investigated thematically. Total 24-h area under the curve (AUCtotal) [glucose] tended to be lower for TRF versus EXF (-5.5 ± 9.0 mmol/L/h, P = 0.09). Nocturnal glucose AUC was lower in TRF (-4.2 ± 5.8 mmol/L/h, P = 0.04), with no difference in waking glucose AUC or AUCtotal for [insulin]. Attitudes towards TRF were positive with improved feelings of well-being. Barriers to TRF were work schedules, family commitments and social events. Compared to extended feeding, short-term TRF improved nocturnal glycemic control and was positively perceived in men with overweight/obesity.

A Time to Eat and a Time to Exercise.

This Perspective for Progress provides a synopsis for the potential of time-restricted eating (TRE) to rescue some of the deleterious effects on circadian biology induced by our modern-day lifestyle. We provide novel insights into the comparative and potential complementary effects of TRE and exercise training on metabolic health.