Acute Effects of Dairy or Soy Milk on Sex Hormones Following Resistance Exercise in Males: A Randomized, Crossover Pilot Trial.

INTRODUCTION: Resistance exercise training (RET) can increase muscle mass and strength, and this adaptation is optimized when dietary protein is consumed to enhance muscle protein synthesis. Dairy milk has been endorsed for this purpose; however, allergy and lactose intolerance affect two-thirds of the global population making dairy milk unsuitable for many. Plant-based alternatives such as soy milk have gained popularity and exhibit comparable protein content. However, concerns regarding soy phytoestrogens potentially influencing circulating sex hormones and diminishing the anabolic response to RET have been raised. This study therefore aimed to assess the acute effects of dairy and soy milk consumption on circulating sex hormones (total, free testosterone, free testosterone percentage, total estrogen, progesterone, and sex hormone binding globulin) after RET. MATERIALS AND METHODS: Six male participants were recruited for a double-blinded, randomized crossover study with either dairy or soy milk provided post RET. Venous samples were collected before and after milk consumption across seven timepoints (0-120 minutes) where circulating sex hormones were analyzed. Two-way ANOVA analyses were applied for repeated measures for each hormone. The area under the curve (AUC) was also calculated between dairy and soy milk. Significance was set at p<0.05. RESULTS: No significant differences were observed in acute circulating serum for free (p=0.95), % free (p=0.56), and total testosterone (p=0.88), progesterone (p=0.67), or estrogen (p=0.21) between milk conditions. Likewise, no significant differences in AUC were observed between any hormones. CONCLUSION: These findings suggest that consumption of dairy milk and soy milk have comparable acute effects on circulating sex hormones following RET. Further investigations with expanded sample sizes are needed to strengthen and broaden these initial findings.

Plant-based and Early Time-restricted Eating for Prevention and Treatment of Type 2 Diabetes in Adults: A Narrative Review.

Type 2 diabetes (T2D) is a significant public health challenge for which effective lifestyle interventions are needed. A growing body of evidence supports the use of both plant-based eating patterns and early time-restricted eating (eTRE) for the prevention and treatment of T2D, but research has not yet explored the potential of these dietary strategies in combination. In this narrative review, we assessed the evidence by which plant-based diets, in conjunction with eTRE, could support T2D care. The electronic databases MEDLINE and the Web of Science were searched for relevant articles published throughout the last decade. Observational research has shown that healthy plant-based eating patterns and eTRE are associated with reductions in T2D risk. Interventional trials demonstrated that plant-based diets promote improvements in glycated hemoglobin, insulin resistance, glycemic management, and cardiometabolic risk factors. These changes may be mediated, in part, by reductions in oxidative stress, dietary acid load, and hepatocellular and intramyocellular lipids. The eTRE strategies were also shown to improve insulin resistance and glycemic management, and mechanisms of action included enhanced regulation of circadian rhythm and increased metabolic flexibility. Integrating these dietary strategies may produce additive benefits, mediated by reduced visceral adiposity and beneficial shifts in gut microbiota composition. However, potential barriers to concurrent implementation of these interventions may exist, including social challenges, scheduling constraints, and tolerance. Prospective trials are needed to examine their acceptability and clinical effects.

Recruitment, retention, and experiences of Australian male dietitians: A cross-sectional online survey.

AIM: Male dietitians are under-represented in the global dietetics workforce, including in Australia. This study explores Australian males' experiences as dietitians in the Australian workforce, with the aim to identify influences that initially attracted them to dietetics, as well as barriers that may affect their decision to stay in or leave the profession. METHODS: A cross-sectional, semi-quantitative web-based survey was distributed to male dietitians using purposive, snowball sampling. Closed and open-ended questions were included. Descriptive statistics were generated, and content analysis of free-text responses identified major themes. RESULTS: Seventy-one respondents opened the survey link, of which 65 respondents attempted the survey. Fifty-four (83.1%) respondents agreed that dietetics is female-dominated. An interest in food and nutrition was the most reported reason for studying dietetics (73.8%). Of the 55 respondents who were not intending to retire in the next 5 years, 15 (27.3%) stated they were somewhat or extremely likely to leave the profession of dietetics. Respondents identified issues that impacted their experiences as a male dietitian, including gender differences, a lack of male role models, barriers to career progression/employment, and perceptions of a lack of respect and impact within healthcare. CONCLUSIONS: Australian male dietitians perceive systemic, social, and personal factors that have influenced their career experiences. Greater exposure to prominent male role models may be self-perpetuating in improving male dietitian recruitment and eventually, retention. A multi-pronged approach is needed to improve the rate of recruitment of male dietitians, with a role for tertiary education providers and peak dietetics bodies.

A comparison of diet quality and cardiovascular and inflammatory responses between aerobically trained male adults following either a long-term vegan or omnivorous dietary pattern.

Vegan dietary patterns are increasingly being adopted by endurance athletes, yet research examining the influence of this dietary pattern on exercise-related physiology is limited. This pilot study, therefore, aimed to explore nutrient status, diet quality and cardiovascular and inflammatory responses in aerobically trained adult males following vegan and omnivorous dietary patterns during aerobic exercise. An incremental ramp running test was used to assess peak oxygen consumption (VO2peak ) in males aged 18-55 years, engaging in >4 h training/week. Exercise testing was performed during walking and steady-state running conditions (60% and 90% of VO2peak ). Participants were grouped by dietary pattern type and were equivalent for age, training volume and VO2peak . When compared to the omnivorous group (n = 8, age 35.6 years, VO2peak 55.7 mL/kg/min), the vegan group (n = 12, age 33.4 years, VO2peak 56.4 m/kg/min) consumed more energy from carbohydrates (p = 0.007), and less energy from protein (p = 0.001) while exhibiting a higher overall diet quality score (p = 0.008). No differences in inflammatory biomarkers were observed before or after running. Total red blood cell count, haemoglobin and haematocrit levels were lower in the vegan dietary group. In summary, aerobically trained males, following a long-term vegan diet, can tolerate a short bout of running broadly comparatively to their omnivore counterparts. More arduous endurance exercise conditions should be explored to further uncover potential outcomes of consuming a vegan dietary pattern and exercise-related physiology.

Examining dietary behaviours, diet quality, motives and supplementation use in physically active individuals following vegetarian-based eating patterns.

The adoption of vegetarian-based dietary patterns among athletes has been gaining popularity. However, limited research examines the dietary behaviours within this group. Therefore, the aim of this study was to examine self-reported dietary behaviours in a cohort of physically active individuals following vegetarian-based dietary patterns, recruited via social media. A 52-item online survey was created with questions related to demographics, physical activity, eating patterns and supplementation use. An external link to the Australian Automated Self-Administered 24-h (ASA24-AU) recall was included to examine nutrient intakes. Dietary quality was assessed using the Alternate Healthy Eating Index-2010 (AHEI-2010) and the Dietary Phytochemical Index (DPI) tools. A total of 781 (84.8%) respondents completed the survey in 2018. Principal motives for adhering to a vegetarian-based dietary pattern included animal rights (86.5%), environmental concerns (75.4%), health reasons (69.6%) and improving physical performance (24.1%). Vitamin B12 was the most commonly reported supplement (58.1%) followed by protein powder (36.3%) and vitamin D (35.9%). A total of 133 respondents completed the ASA24-AU dietary recall with generally adequate nutrient intakes and a high-quality diet as assessed by the AHEI-2010 and DPI. A significant minority of physically active individuals following vegetarian-based diets do so with the aspiration of improving their exercise performance. Dietary quality was considered high in this group for recreational physical activity, although intakes of vitamin B12 and LC n-3 PUFA were low.

A Cross-Sectional Comparison of the Whole Blood Fatty Acid Profile and Omega-3 Index of Male Vegan and Omnivorous Endurance Athletes.

Background: Evaluation of the dietary fat consumption in athletes following vegan diets is scarce. The aim of this study was to explore the intakes, availability, and uptake of physiologically relevant fatty acids into whole blood, and consequently the Omega-3 Index (O3I) of endurance athletes following vegan and omnivorous dietary patterns.Materials: Males aged 18 to 55 years, engaging in ≥ four hours of training/week and following a vegan (>6 months) or omnivorous dietary pattern were eligible to participate. A 7-day food and training diary was collected and an incremental ramp running protocol used to determine peak aerobic capacity. A finger prick blood sample was collected to determine the whole blood fatty acid profile and O3I. Participants were grouped as following a vegan or omnivorous diet matched for age, training volume and peak aerobic capacity.Results: The vegan group (n = 12) consumed significantly less dietary total fat (122.2 g/day vs 84.1 g/day p = 0.007), saturated fat (43.74 g/day vs 18.42 g/day p < 0.0001), monounsaturated fat (49.6 g/day vs 35.64 g/day p = 0.039) and long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) compared to the omnivorous group (n = 8). Between group differences in whole blood fatty acid concentrations were observed including; linoleic, eicosapentaenoic, docosahexaenoic, n-6:n-3 and AA:EPA ratios. O3I in both groups were suboptimal (vegan: 4.13%, omnivorous: 5.40%) in terms of cardiac risk.Conclusion: Male endurance athletes should ensure their dietary LC n-3 PUFA intakes, particularly EPA and DHA fatty acids are sufficient to optimize their O3I.

Limitations with the Digestible Indispensable Amino Acid Score (DIAAS) with Special Attention to Plant-Based Diets: a Review.

PURPOSE OF REVIEW: This review describes several limitations of the Digestible Indispensable Amino Acid Score (DIAAS) with a focus on its application to plant-based dietary patterns. RECENT FINDINGS: Evaluating protein quality in terms of digestibility is paramount to support and optimize the health and well-being of human populations in situations where food insecurity and protein energy malnutrition are widespread. The Food and Agriculture Organization (FAO) of the United Nations has endorsed the DIAAS to replace the previously recommended Protein Digestibility Corrected Amino Acid Score (PDCAAS) for protein quality assessment. While multiple strengths characterize the DIAAS, substantial limitations remain, many of which are accentuated in the context of a plant-based dietary pattern. Some of these limitations include a failure to translate differences in nitrogen-to-protein conversion factors between plant- and animal-based foods, limited representation of commonly consumed plant-based foods within the scoring framework, inadequate recognition of the increased digestibility of commonly consumed heat-treated and processed plant-based foods, its formulation centered on fast-growing animal models rather than humans, and a focus on individual isolated foods vs the food matrix. The DIAAS is also increasingly being used out of context where its application could produce erroneous results such as exercise settings. When investigating protein quality, particularly in a plant-based dietary context, the DIAAS should ideally be avoided.

Limitations of the Digestible Indispensable Amino Acid Score (DIAAS) and Choice of Statistical Reporting. Comment on "A Comparison of Dietary Protein Digestibility, Based on DIAAS Scoring, in Vegetarian and Non-Vegetarian Athletes. Nutrients 2019, 11, 3106".

Dear Editor, [...].

Vegetarian-Based Dietary Patterns and their Relation with Inflammatory and Immune Biomarkers: A Systematic Review and Meta-Analysis.

Dietary patterns with substantial proportions of energy from plant sources have been associated with favorable biomarkers of low-grade inflammation. Less is known of the relation between vegetarian-based dietary patterns and markers of inflammation and immune status. This systematic review and meta-analysis aimed to determine the relation between vegetarian-based dietary patterns and inflammatory and immune markers (C-reactive protein, tumour necrosis factor α, fibrinogen, natural killer cells, leukocytes, lymphocytes, thrombocytes, interleukins, and immunoglobulins). PubMed, Medline, and Cochrane scientific databases were searched to identify relevant studies. Random effects meta-analyses were conducted to assess the weighted mean differences (WMDs) for each outcome variable between vegetarian and non-vegetarian groups. Thirty observational and 10 intervention studies were included in the review. Pooled effects of vegetarian-based dietary patterns were associated with significantly lower concentrations of CRP (WMD: -0.61 mg/L; 95% CI: -0.91, -0.32 mg/L; P = 0.0001), fibrinogen (WMD: -0.22 g/L; 95% CI: -0.41, -0.04 mg/L; P = 0.02), and total leukocyte (WMD: -0.62 × 10(3)/µL; 95% CI -1.13 × 10(3), -0.10 × 10(3)/µL; P = 0.02) compared with those following non-vegetarian dietary patterns in observational studies. Insufficient data were identified for a meta-analysis of intervention studies. This study provides evidence that vegetarian-based dietary patterns are associated with lowered serum C-reactive protein, fibrinogen, and total leukocyte concentrations. Future research should focus on large-scale intervention trials, contrasting differences in inflammation and immune status and function between vegetarian and non-vegetarian-based populations.

Vegetarian and Omnivorous Nutrition - Comparing Physical Performance.

Humans consuming vegetarian-based diets are observed to have reduced relative risk for many chronic diseases. Similarly, regular physical activity has also been shown to assist in preventing, and reducing the severity of these conditions. Many people, including athletes, acknowledge these findings and are adopting a vegetarian-based diet to improve their health status. Furthermore, athletes are incorporating this approach with the specific aim of optimizing physical performance. To examine the evidence for the relationship between consuming a predominately vegetarian-based diet and improved physical performance, a systematic literature review was performed using the SCOPUS database. No date parameters were set. The keywords vegetarian OR vegan AND sport OR athlete OR training OR performance OR endurance were used to identify relevant literature. Included studies (i) directly compared a vegetarian-based diet to an omnivorous/mixed diet, (ii) directly assessed physical performance, not biomarkers of physical performance, and (iii) did not use supplementation emulating a vegetarian diet. Reference lists were hand searched for additional studies. Seven randomized controlled trials and one cross-sectional study met the inclusion criteria. No distinguished differences between vegetarian-based diets and omnivorous mixed diets were identified when physical performance was compared. Consuming a predominately vegetarian-based diet did not improve nor hinder performance in athletes. However, with only 8 studies identified, with substantial variability among the studies' experimental designs, aims and outcomes, further research is warranted.