Effect of nutritional interventions on the psychological symptoms of premenstrual syndrome in women of reproductive age: a systematic review of randomized controlled trials.

CONTEXT: Premenstrual syndrome (PMS) affects approximately 48% of women of reproductive age worldwide. It can lead to functional impairment, lower quality of life, and decreased work productivity. Despite the availability of medical treatment options, women are seeking alternative interventions because of concerns of harmful side effects and limited evidence of efficacy associated with pharmacological treatments. To date, high-quality research investigating the effects of dietary and nutrient intervention on PMS is limited. OBJECTIVE: This systematic review investigated the effect of nutritional interventions on the psychological symptoms of PMS. DATA SOURCES: Five electronic databases were searched for randomized controlled trials (RCTs) published in English from inception to October 2022. Trials eligible for inclusion were nutritional intervention studies involving women of reproductive age that measured PMS-associated psychological outcomes. DATA EXTRACTION: Articles were selected using prespecified inclusion criteria. Data screening and extraction and risk-of-bias assessments were conducted by 3 independent reviewers using article screening software and the Cochrane Risk of Bias 2 tool. DATA ANALYSIS: Thirty-two articles reporting on 31 RCTs involving 3254 participants, ranging in age from 15 to 50 years were included and narratively reviewed. Only 1 of the included studies had a low risk of bias. Treatment with vitamin B6, calcium, and zinc consistently had significant positive effects on the psychological symptoms of PMS. There was insufficient evidence to support the effects of vitamin B1, vitamin D, whole-grain carbohydrates, soy isoflavones, dietary fatty acids, magnesium, multivitamin supplementation, or PMS-specific diets. CONCLUSIONS: There is some evidence to support the use of nutritional interventions for improving psychological symptoms of PMS. However, more research using consistent protocols, procedures to minimize risk of bias, intention-to-treat analysis, and clearer reporting is required to provide conclusive nutritional recommendations for improving PMS-related psychological outcomes. PROSPERO REGISTRATION NO: CRD42022369999.

Nut Consumption and Fertility: a Systematic Review and Meta-Analysis.

The high concentration of omega-3 polyunsaturated fats, dietary fibers, vitamins, minerals, and polyphenols found in nuts suggest their regular consumption may be a simple strategy for improving reproductive health. This systematic review and meta-analysis aimed to present up-to-date evidence regarding the association between nut intake and fertility outcomes in males and females. Ovid MEDLINE, Embase, CINAHL, and Scopus were searched from inception to 30 June 2023. Eligible articles were interventional or observational studies in human subjects of reproductive age (18-49 y) that assessed the effects (or association) of dietary nut consumption (for a minimum of 3 mo) on fertility-related outcomes. Random-effects meta-analyses were completed to produce a pooled effect estimate of nut consumption on sperm total motility, vitality, morphology, and concentration in healthy males. Four studies involving 875 participants (646 males, 229 females) were included in this review. Meta-analysis of 2 RCTs involving 223 healthy males indicated consumption of ≥ 60g nuts/d increased sperm motility, vitality, and morphology in comparison to controls but had no effect on sperm concentration. Nonrandomized studies reported no association between dietary nut intake and conventional sperm parameters in males, embryo implantation, clinical pregnancy or live birth in males and females undergoing ART. Our meta-analysis shows that including at least 2 servings of nuts daily as part of a Western-style diet in healthy males improves sperm parameters, which are predictors of male fertility. Due to their nutritional profile, nuts were found to have potential to promote successful reproductive outcomes. This trial was registered at PROSPERO (CRD42020204586).

Exploring the determinants of food choice in Chinese immigrants living in Australia and Chinese people living in mainland China: A qualitative study.

BACKGROUND: The present study aimed to qualitatively explore the food choice determinants of both Chinese immigrants living in Australia and Chinese people living in mainland China. METHODS: Eight Chinese Australian participants (female, n = 5; male, n = 3) and ten mainland Chinese participants (female, n = 5; male, n = 5) were recruited from Australia (primarily in Melbourne, Victoria) and China (predominantly in Zhengzhou, Henan province) between June 2021 and March 2022. Participants were diverse in age, socio-economic background, occupation and health status. Semi-structured in-depth interviews were conducted in Mandarin either face-to-face or using online video/voice calls. Interviews were audio-recorded and transcribed verbatim. Investigator triangulation was used to enhance scientific rigour. RESULTS: Four themes were identified: (1) food choice determinants were shaped by traditional and modern nutrition perceptions and personal food philosophy; (2) physiological responses to food provide direct feedback that impacts future food choices; (3) consideration of convenience was a predominant influencer of food choice; and (4) the differences in food environments between China and Australia promoted distinctive food choice determinants for Chinese people. CONCLUSIONS: Chinese Australian and mainland Chinese participants' food choices are shaped by traditional Chinese nutrition philosophy, modern Western nutrition science and the contemporary food environment. There are clear cultural characteristics in their food choice determinants that should be considered by health educators, nutrition professionals and nutrition policymakers when developing culturally appropriate health interventions for Chinese people.

How and Why Diets Change Post-Migration: A Qualitative Exploration of Dietary Acculturation among Recent Chinese Immigrants in Australia.

Chinese immigrants living in Western countries are at increased risk for cardiometabolic diseases. Dietary acculturation has been implicated as a potential contributor, but little is known about why diets change post-migration. The purpose of this qualitative research study was to explore how and why diets change post-migration for Chinese immigrants living in Australia. Eleven participants undertook semi-structured interviews exploring and comparing their diets when they lived in China to their post-migration diets. Thematic analysis revealed that participants exhibited changed social structures of meal preparation, and made unacknowledged dietary changes, such as recipe modification, to maintain their traditional Chinese diet post-migration. Implications of both deliberate and unrecognized dietary changes post-migration include connections to increased risk for metabolic disease post-migration.

A single, high-fat meal adversely affects postprandial endothelial function: a systematic review and meta-analysis.

BACKGROUND: Endothelial dysfunction is a predictive risk factor for the development of atherosclerosis and is assessed by flow-mediated dilation (FMD). Although it is known that NO-dependent endothelial dysfunction occurs after consuming a high-fat meal, the magnitude of the effect and the factors that affect the response are unquantified. OBJECTIVES: We conducted a systematic review and meta-analysis exploring the quantitative effects of a single high-fat meal on endothelial function and determined the factors that modify the FMD response. METHODS: Six databases were systematically searched for original research published up to January 2022. Eligible studies measured fasting and postprandial FMD following consumption of a high-fat meal. Meta-regression was used to analyze the effect of moderator variables. RESULTS: There were 131 studies included, of which 90 were suitable for quantitative meta-analysis. A high-fat meal challenge transiently caused endothelial dysfunction, decreasing postprandial FMD at 2 hours [-1.02 percentage points (pp); 95% CI: -1.34 to -0.70 pp; P < 0.01; I2 = 93.3%], 3 hours [-1.04 pp; 95% CI: -1.48 to -0.59 pp; P < 0.001; I2 = 84.5%], and 4 hours [-1.19 pp; 95% CI: -1.53 to -0.84 pp; P < 0.01; I2 = 94.6%]. Younger, healthy-weight participants exhibited a greater postprandial reduction in the FMD percentage change than older, heavier, at-risk groups after a high-fat meal ( P < 0.05). The percentage of fat in the meals was inversely associated with the magnitude of postprandial changes in FMD at 3 hours (P < 0.01). CONCLUSIONS: A single, high-fat meal adversely impacts endothelial function, with the magnitude of the impact on postprandial FMD moderated by the fasting FMD, participant age, BMI, and fat content of the meal. Recommendations are made to standardize the design of future postprandial FMD studies and optimize interpretation of results, as high-fat meals are commonly used in clinical studies as a challenge to assess endothelial function and therapeutics. This trial was registered at PROSPERO as CRD42020187244.

Study protocol for the Shifting Weight using Intermittent Fasting in night shift workers (SWIFt) study: a three-arm randomised controlled trial comparing three weight loss strategies in night shift workers with obesity.

INTRODUCTION: Shift workers are at an increased risk of developing obesity and type 2 diabetes. Eating and sleeping out of synchronisation with endogenous circadian rhythms causes weight gain, hyperglycaemia and insulin resistance. Interventions that promote weight loss and reduce the metabolic consequences of eating at night are needed for night shift workers. The aim of this study is to examine the effects of three weight loss strategies on weight loss and insulin resistance (HOMA-IR) in night shift workers. METHODS AND ANALYSIS: A multisite 18-month, three-arm randomised controlled trial comparing three weight loss strategies; continuous energy restriction; and two intermittent fasting strategies whereby participants will fast for 2 days per week (5:2); either during the day (5:2D) or during the night shift (5:2N). Participants will be randomised to a weight loss strategy for 24 weeks (weight loss phase) and followed up 12 months later (maintenance phase). The primary outcomes are weight loss and a change in HOMA-IR. Secondary outcomes include changes in glucose, insulin, blood lipids, body composition, waist circumference, physical activity and quality of life. Assessments will be conducted at baseline, 24 weeks (primary endpoint) and 18 months (12-month follow-up). The intervention will be delivered by research dietitians via a combination of face-to-face and telehealth consultations. Mixed-effect models will be used to identify changes in dependent outcomes (weight and HOMA-IR) with predictor variables of outcomes of group, time and group-time interaction, following an intention-to-treat approach. ETHICS AND DISSEMINATION: The study protocol was approved by Monash Health Human Research Ethics Committee (RES 19-0000-462A) and registered with Monash University Human Research Ethics Committee. Ethical approval has also been obtained from the University of South Australia (HREC ID: 202379) and Ambulance Victoria Research Committee (R19-037). Results from this trial will be disseminated via conference presentations, peer-reviewed journals and student theses. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN-12619001035112).

The Effect of Dietary Patterns on Clinical Pregnancy and Live Birth Outcomes in Men and Women Receiving Assisted Reproductive Technologies: A Systematic Review and Meta-Analysis.

The nutritional status of reproductive-aged couples can have a significant impact on fertility status, but the effect of dietary patterns on pregnancy outcomes in people using assisted reproductive technologies (ARTs) is currently unknown. This review aimed to synthesize the published research investigating the relation between preconception dietary patterns and clinical pregnancy or live birth in men and women of reproductive age undergoing ART. Six electronic databases were systematically searched for original research published between January 1978 and June 2021. Original research reporting on the effect of predefined dietary patterns on either clinical pregnancy and/or live birth rates following in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in men and women aged 18-49 y was eligible for inclusion. Studies were assessed for risk of bias according to the Cochrane guidelines. Included studies underwent qualitative and quantitative synthesis using random-effects model meta-analyses. Thirteen studies (12 cohort studies, 1 randomized controlled trial) reporting on 3638 participants (93% female) were included in the review. All studies had a moderate-high risk of bias. In individual studies, maternal adherence to 4 dietary patterns [Mediterranean diet (RR: 1.22; 95% CI: 1.05, 1.43), novel profertility diet (OR: 1.43; 95% CI: 1.19, 1.72), Iranian traditional medicine diet (OR: 3.9; 95% CI: 1.2, 12.8), Dutch national dietary recommendations diet (OR: 1.65; 95% CI: 1.08, 2.52)] was associated with increased likelihood of achieving a clinical pregnancy, while 2 dietary patterns [novel profertility diet (OR: 1.53; 95% CI: 1.26, 1.85), Mediterranean diet (RR: 1.25; 95% CI: 1.07, 1.45)] were associated with increased probability of live birth. Meta-analyses showed an association between adherence to the Mediterranean dietary pattern and live birth across 2 studies (OR: 1.98; 95% CI: 1.17, 3.35; I2 = 29%, n = 355), but no association with clinical pregnancy. As the relation between dietary patterns and ART outcomes is currently inconsistent, higher-quality nutrition research is required to further explore this emerging field of interest (PROSPERO registration: CRD42020188194).

Exploring the Determinants of Food Choice in Chinese Mainlanders and Chinese Immigrants: A Systematic Review.

Determinants of food choice in Chinese populations have not been systematically synthesised using a cultural lens. This study reviewed qualitative studies exploring food choice determinants of both Chinese mainlanders and Chinese immigrants living in Western countries. Ovid Medline, CINAHL Plus, Web of Science, ProQuest, and China National Knowledge Infrastructure database (CNKI) were searched from database inception to 1 April 2021. Studies were included if they involved qualitative research methods, were written in English or Chinese, investigated the factors influencing food choices, and targeted Chinese mainlanders or Chinese immigrants living in Western countries. Twenty-five studies (24 in English, 1 in Chinese) were included, involving 2048 participants. Four themes were identified; (1) the principles of traditional Chinese medicine (TCM), (2) perceptions of a healthy diet in Chinese culture (e.g., regular eating, eating in moderation, and emphasis on food freshness), (3) the desire to maintain harmony in families/communities, and (4) physical/social environmental factors all significantly influenced Chinese people's food choices. It is important to acknowledge these factors when developing culturally appropriate nutrition programs for promoting health in Chinese mainlanders and Chinese immigrants.

Food Insecurity Prevalence, Severity and Determinants in Australian Households during the COVID-19 Pandemic from the Perspective of Women.

This study aimed to describe the prevalence, severity and socio-demographic predictors of food insecurity in Australian households during the COVID-19 pandemic in 2020, from the perspective of women. A cross-sectional online survey of Australian (18-50 years) women was conducted. The survey collected demographic information and utilised the 18-item US Department of Agriculture Household Food Security Survey Module and the Kessler Psychological Distress Scale (K10). A multivariable regression was used to identify predictors of food security status. In this cohort (n = 1005), 19.6% were living in households experiencing food insecurity; with 11.8% experiencing low food-security and 7.8% very low food-security. A further 13.7% of households reported marginal food-security. Poor mental health status (K10 score ≥ 20) predicted household food insecurity at all levels. The presence of more than three children in the household was associated with low food-security (OR 6.24, 95% CI: 2.59-15.03). Those who were renting were 2.10 (95% CI: 1.09-4.05) times likely to experience very low food-security than those owning their own home. The COVID-19 pandemic may have contributed to an increased prevalence of household food insecurity. This study supports the need for a range of responses that address mental health, financial, employment and housing support to food security in Australia.

Processed foods drive intestinal barrier permeability and microvascular diseases.

Intake of processed foods has increased markedly over the past decades, coinciding with increased microvascular diseases such as chronic kidney disease (CKD) and diabetes. Here, we show in rodent models that long-term consumption of a processed diet drives intestinal barrier permeability and an increased risk of CKD. Inhibition of the advanced glycation pathway, which generates Maillard reaction products within foods upon thermal processing, reversed kidney injury. Consequently, a processed diet leads to innate immune complement activation and local kidney inflammation and injury via the potent proinflammatory effector molecule complement 5a (C5a). In a mouse model of diabetes, a high resistant starch fiber diet maintained gut barrier integrity and decreased severity of kidney injury via suppression of complement. These results demonstrate mechanisms by which processed foods cause inflammation that leads to chronic disease.

Effect of Dietary Acetic Acid Supplementation on Plasma Glucose, Lipid Profiles, and Body Mass Index in Human Adults: A Systematic Review and Meta-analysis.

BACKGROUND: Acetic acid is a short-chain fatty acid that has demonstrated biomedical potential as a dietary therapeutic agent for the management of chronic and metabolic illness comorbidities. In human beings, its consumption may improve glucose regulation and insulin sensitivity in individuals with cardiometabolic conditions and type 2 diabetes mellitus. Published clinical trial evidence evaluating its sustained supplementation effects on metabolic outcomes is inconsistent. OBJECTIVE: This systematic review and meta-analysis summarized available evidence on potential therapeutic effects of dietary acetic acid supplementation via consumption of acetic acid-rich beverages and food sources on metabolic and anthropometric outcomes. METHODS: A systematic search was conducted in Medline, Scopus, EMBASE, CINAHL Plus, and Web of Science from database inception until October 2020. Randomized controlled trials conducted in adults evaluating the effect of dietary acetic acid supplementation for a minimum of 1 week were included. Meta-analyses were performed using a random-effects model on fasting blood glucose (FBG), triacylglycerol (TAG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), glycated hemoglobin (HbA1c), body mass index (BMI), and body fat percentage. Statistical heterogeneity was assessed by calculation of Q and I2 statistics, and publication bias was assessed by calculation of Egger's regression asymmetry and Begg's test. RESULTS: Sixteen studies were included, involving 910 participants who consumed between 750 and 3600 mg acetic acid daily in interventions lasting an average of 8 weeks. Dietary acetic acid supplementation resulted in significant reductions in TAG concentrations in overweight and obese but otherwise healthy individuals (mean difference [MD] = -20.51 mg/dL [95% confidence intervals = -32.98, -8.04], P = .001) and people with type 2 diabetes (MD = -7.37 mg/dL [-10.15, -4.59], P < .001). Additionally, acetic acid supplementation significantly reduced FBG levels (MD = -35.73 mg/dL [-63.79, -7.67], P = .01) in subjects with type 2 diabetes compared with placebo and low-dose comparators. No other changes were seen for other metabolic or anthropometric outcomes assessed. Five of the 16 studies did not specify the dose of acetic acid delivered, and no studies measured blood acetate concentrations. Only one study controlled for background acetic acid-rich food consumption during intervention periods. Most studies had an unclear or high risk of bias. CONCLUSION: Supplementation with dietary acetic acid is well tolerated, has no adverse side effects, and has clinical potential to reduce plasma TAG and FBG concentrations in individuals with type 2 diabetes, and to reduce TAG levels in people who are overweight or obese. No significant effects of dietary acetic acid consumption were seen on HbA1c, HDL, or anthropometric markers. High-quality, longer-term studies in larger cohorts are required to confirm whether dietary acetic acid can act as an adjuvant therapeutic agent in metabolic comorbidities management.

Nut Consumption for Cognitive Performance: A Systematic Review.

Diet is considered an important modifiable lifestyle factor capable of attenuating early cognitive changes in healthy older people. The inclusion of nuts in the diet has been investigated as a dietary strategy for maintenance of brain health across the lifespan. This review aimed to present up-to-date evidence regarding the association between nut intake and cognitive performance. Four databases (Ovid MEDLINE, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus, and Embase) were systematically searched from inception to April 2020. Eligible articles were interventional or observational studies in humans aged ≥18 y that measured the effects (or association) of nuts (almond, hazelnut, macadamia, pistachio, walnut, pecan, pine nut, Brazil nut, cashew, peanut) on cognitive outcomes. Out of the 2374 articles identified in the searches, 22 involving 43,793 participants met the criteria and were ultimately included in this review. Memory (immediate and delayed), attention, processing speed, executive function, and visual-spatial ability, as well as risk of mild cognitive impairment, were the outcomes investigated. Lack of consistency across the studies regarding study design, types of nut used, and cognitive outcomes measured resulted in inconsistent evidence that the regular consumption of mixed nuts has a protective effect on cognition in adults of different ages. Nonetheless, we observed that studies targeting populations with a higher risk of cognitive decline tended to find a more favorable outcome. Furthermore, homogeneous findings were observed in the studies that specifically addressed the association between walnut consumption and cognitive performance: out of the 6 studies, including 2 randomized controlled trials, only 1 did not find a positive association.

Assessment of Dietary Acculturation in East Asian Populations: A Scoping Review.

East Asian immigrants face multiple challenges upon arrival in their destination country, including an increased risk of future diabetes and cardiovascular disease development. The adoption of food and eating patterns of their host country (i.e., dietary acculturation) may contribute to this increased disease risk. To effectively examine the dietary acculturation-disease risk relationship in East Asian immigrants, sensitive tools are necessary; however, there has been no systematic review of the methods used to assess dietary acculturation in this population. A systematic scoping review of the literature was undertaken to address this gap. A systematic search was conducted in December 2019 and returned a total of 6140 papers. Manuscripts were screened independently by 2 reviewers, resulting in the final inclusion of 30 papers reporting on 27 studies. Robust measures of dietary acculturation were lacking, with only 6 studies using validated tools. Most studies used self-reported cross-sectional surveys to determine how the individual's diet had changed since immigrating, with responses provided on Likert scales. Only 3 quantitative longitudinal studies used prospective measures of diet change, through serial food-frequency questionnaires. Qualitative studies explored dietary acculturation and factors influencing change in diet through semi-structured interviews and focus groups.  This review found there is no consensus in the literature on how to most effectively measure the magnitude and process of dietary acculturation in East Asian populations. There is a need for robust, longitudinal, and mixed-method study designs to address the lack of evidence and develop more comprehensive tools measuring dietary acculturation. Improving the assessment methods used to measure dietary acculturation is critical in helping to monitor the impact of interventions or policies aimed at reducing diet-related disease risk in East Asian immigrant populations.

Not Scared of Sugar™: Outcomes of a structured type 2 diabetes group education program for Chinese Australians.

Type 2 diabetes disproportionately affects the Chinese population yet there are no structured diabetes education programs specifically designed for this community in Australia. This project aimed to develop and evaluate a pilot type 2 diabetes group education program designed specifically for Chinese migrants living in Australia. A non-randomised pre- versus post-intervention trial was conducted between March 2017 and November 2018. A culturally tailored group education program (Not Scared of Sugar™) was developed and piloted with Melbourne-based Cantonese-speaking people with type 2 diabetes. Program teaching styles were aligned with the Confucian cultural process of learning and incorporated culturally specific strategies to promote healthy behaviour change. Thirty-four individuals (35% male) attended five education sessions over ten weeks, delivered by a Cantonese-speaking facilitator and multidisciplinary clinicians. Data were collected from participants at baseline, on program completion and at 6 months follow-up. Mean (SD) participant age was 69 (9) years, with a mean time of 25.7 (10.8) years in Australia and a median duration of diabetes of 10 (IQR = 2.8-20.5) years. At program completion, mean participant waist circumference (90.5 versus 89.2 cm, p < .001) and waist-to-height ratio (0.574 vs. 0.566, p < .001) was significantly reduced and both were further reduced at 6-month follow-up (p < .05). There was a significant increase in the median frequency of diabetes self-care behaviours undertaken, with American Association of Diabetes Educators Questionnaire Score: 30 (22-32.3) versus 33 (29.8-35.0), p < .001 at 6-month follow-up. Diabetes-related distress assessed by PAID-C was also significantly reduced at 6-month follow-up (p < .05). Mean HbA1c was unchanged after 6 months; 51 (7.9) versus 50 (7.8) mmol/mol, p = .316. Program attrition was 6%. Not Scared of Sugar™ successfully reduced waist circumference, increased diabetes self-management behaviours and reduced diabetes distress in Cantonese-speaking Australians, which may positively impact long-term risk of vascular complications.

Health Benefits of Whey or Colostrum Supplementation in Adults ≥35 Years; a Systematic Review.

Food-health claims are an important method of translating nutrition research to consumers. Whey and colostrum are thought to exert health benefits to adults, but it is unclear what measurable, objective health benefits they impart. This review aimed to identify the objective health benefits of bovine whey or colostrum-based beverages to healthy adults aged ≥35 years to substantiate a food-health claim. Seven databases were systematically searched. Eligible articles were RCTs that involved healthy adults aged ≥35 years, consuming whey or colostrum in beverage form and measuring objective health markers. Quality assessment and data extraction was conducted in duplicate. The searches identified 9943 papers and 16 were included in this review; 13 studies, reported across 15 papers, related to whey, one study to colostrum. The outcomes identified were body composition, bone mineral density, biochemical markers, such as blood glucose and lipids, and muscle strength and synthesis. Heterogeneous outcomes, high risk of bias and inconsistent findings resulted in inconclusive evidence to substantiate a food-health claim. Clearer reporting and consensus on a minimum set of objective measures would allow for more robust recommendations regarding food-health claims. Protecting consumers from misleading health claims will require collaboration between regulators, researchers, and the food industry.

An Autoethnographic Account of a Bicultural Clinician-Researcher Applying New Evidence of Chinese Diabetes Education Into Practice.

Introduction: A clinician-researcher in translational research fulfils obligations in care provision and knowledge generation. Similarly, a bicultural clinician could struggle to switch between cultural paradigms. The purpose of this study was to explore the in-depth experience of multiple roles as a bicultural clinician-researcher in a translational research study. Methods: This study employed an autoethnographical method, where the first author, an Australian-trained Chinese researcher, was the research instrument who critically sought understanding of her experience in relation to culture in the context of translating an evidence-based culturally tailored Chinese diabetes education program into practice. Data were thematically analyzed and triangulated. Results: Specific research-to-practice dilemmas and personal and professional growth experiences were encountered. Learning to be flexible in addressing patients' needs while concurrently collecting program evaluation data was complicated by self-doubt and inflexible colleagues. Implication: Despite challenges, conducting translational research with clinician-researcher can enhance understanding of the different stakeholder cultures, promoting rapid practice change.

The Impact of Time of Day on Energy Expenditure: Implications for Long-Term Energy Balance.

There is evidence to indicate that the central biological clock (i.e., our endogenous circadian system) plays a role in physiological processes in the body that impact energy regulation and metabolism. Cross-sectional data suggest that energy consumption later in the day and during the night is associated with weight gain. These findings have led to speculation that when, as well as what, we eat may be important for maintaining energy balance. Emerging literature suggests that prioritising energy intake to earlier during the day may help with body weight maintenance. Evidence from tightly controlled acute experimental studies indicates a disparity in the body's ability to utilise (expend) energy equally across the day and night. Energy expenditure both at rest (resting metabolic rate) and after eating (thermic effect of food) is typically more efficient earlier during the day. In this review, we discuss the key evidence for a circadian pattern in energy utilisation and balance, which depends on meal timing. Whilst there is limited evidence that simply prioritising energy intake to earlier in the day is an effective strategy for weight loss, we highlight the potential benefits of considering the role of meal timing for improving metabolic health and energy balance. This review demonstrates that to advance our understanding of the contribution of the endogenous circadian system toward energy balance, targeted studies that utilise appropriate methodologies are required that focus on meal timing and frequency.

Metabolic Effects of Resistant Starch Type 2: A Systematic Literature Review and Meta-Analysis of Randomized Controlled Trials.

Published evidence exploring the effects of dietary resistant starch (RS) on human cardiometabolic health is inconsistent. This review aimed to investigate the effect of dietary RS type 2 (RS2) supplementation on body weight, satiety ratings, fasting plasma glucose, glycated hemoglobin (HbA1c), insulin resistance and lipid levels in healthy individuals and those with overweight/obesity, the metabolic syndrome (MetS), prediabetes or type 2 diabetes mellitus (T2DM). Five electronic databases were searched for randomized controlled trials (RCTs) published in English between 1982 and 2018, with trials eligible for inclusion if they reported RCTs involving humans where at least one group consumed ≥ 8 g of RS2 per day and measured body weight, satiety, glucose and/or lipid metabolic outcomes. Twenty-two RCTs involving 670 participants were included. Meta-analyses indicated that RS2 supplementation significantly reduced serum triacylglycerol concentrations (mean difference (MD) = -0.10 mmol/L; 95% CI -0.19, -0.01, P = 0.03) in healthy individuals (n = 269) and reduced body weight (MD = -1.29 kg; 95% CI -2.40, -0.17, P = 0.02) in people with T2DM (n = 90). However, these outcomes were heavily influenced by positive results from a small number of individual studies which contradicted the conclusions of the majority of trials. RS2 had no effects on any other metabolic outcomes. All studies ranged from 1-12 weeks in duration and contained small sample sizes (10-60 participants), and most had an unclear risk of bias. Short-term RS2 supplementation in humans is of limited cardiometabolic benefit.

Modulation of the Gut Microbiota by Resistant Starch as a Treatment of Chronic Kidney Diseases: Evidence of Efficacy and Mechanistic Insights.

Chronic kidney disease (CKD) has been associated with changes in gut microbial ecology, or "dysbiosis," which may contribute to disease progression. Recent studies have focused on dietary approaches to favorably alter the composition of the gut microbial communities as a treatment method in CKD. Resistant starch (RS), a prebiotic that promotes proliferation of gut bacteria such as Bifidobacteria and Lactobacilli, increases the production of metabolites including short-chain fatty acids, which confer a number of health-promoting benefits. However, there is a lack of mechanistic insight into how these metabolites can positively influence renal health. Emerging evidence shows that microbiota-derived metabolites can regulate the incretin axis and mitigate inflammation via expansion of regulatory T cells. Studies from animal models and patients with CKD show that RS supplementation attenuates the concentrations of uremic retention solutes, including indoxyl sulfate and p-cresyl sulfate. Here, we present the current state of knowledge linking the microbiome to CKD, we explore the efficacy of RS in animal models of CKD and in humans with the condition, and we discuss how RS supplementation could be a promising dietary approach for slowing CKD progression.