Nutrition plays a pivotal role in health and disease prevention and management and through its interactions with social and personal factors, influences an individual's growth, development and life chances, as well as long-term health and longevity. These factors include amongst others, genetic inheritance, ethnicity, socio-cultural context, sex and gender. Although different interpretations exist, in general sex refers to the genetic, biological and physiological attributes that distinguish females, males and intersex whereas gender refers to socio-cultural and politically constructed roles and behaviours associated with a feminine, masculine or non-binary identity, which vary from society to society. Sex has implications for key biological processes involving food and nutrients as well as life-stage differences in nutritional requirements. Sex and gender may have implications in how individuals engage in different dietary behaviours and respond to nutrition interventions. The Irish Section Nutrition Society 2023 Conference sought to enhance understanding of the role of sex and gender in nutrition research; explore the influence of sex and gender on risk of non-communicable diseases and examine sex- and gender-specific considerations across the life course. This short editorial provides an overview and highlights of the conference.

For some 20 years, science funding bodies have been asking for the integration of sex- and gender-related factors into the content of research and innovation. The rationale for those requirements has been the accumulated evidence that sex and gender are important determinants of health and disease. The European Commission (EC) has been the first, since 2002, to seriously ask for the integration of sex and gender into research and innovation in the context of their multi-annual framework programmes. When introduced, this condition was not immediately applauded by the research community, who perhaps lacked training in methods for the integration of sex- and gender-related factors. The EC Expert Group on Gendered Innovations sought to fill this gap. This review describes the work of this international collaborative project which has resulted in the development of general and field-specific methods for sex and gender analysis and 38 case studies for various research domains (science, health and medicine, environment, engineering) to illustrate how, by applying methods of sex and gender analysis, new knowledge could be created. Since 2010, science funding bodies in Canada, the USA and several EU member states have followed the example of the EC issuing similar conditions. Although the effects of nutritional patterns on a range of (physiological and health) outcomes may differ for men and women, sex and gender analyses are rarely conducted in nutrition research. In this review, we provide examples of how gender is connected to dietary intake, and how advancing gender analysis may inform gender-sensitive policies and dietary recommendations.

The purpose of the present article is to describe the current state of sex and gender data collection in nutrition science research, discuss the effects of flawed data collection practices, highlight considerations for transgender and gender non-conforming populations and propose a sex- and gender-informed approach to human subjects research. Sex and gender are separate constructs that are often conflated in nutrition research and practice. Current nutrition surveillance programmes in the United States, United Kingdom and Ireland do not accurately capture sex and gender data, which undermines the accuracy of the analyses and excludes gender minorities. Transgender and gender non-conforming populations have distinct clinical and psychosocial nutrition considerations that require further research to inform nutrition policy and practice, such as anthropometric and biochemical changes with hormone therapy, eating disorders, food insecurity and nutrition as a source of empowerment or expression of gender identity. Researchers can apply a sex- and gender-informed approach to human subjects research by treating sex and gender as separate, relevant demographic data, appreciating gender as a fluid construct, and approaching data collection on gender minorities with sensitivity to privacy and confidentiality.

Calcium and vitamin D have well-established roles in maintaining calcium balance and bone health. Decades of research in human subjects and animals have revealed that calcium and vitamin D also have effects on many other organs including male reproductive organs. The presence of calcium-sensing receptor, vitamin D receptor, vitamin D activating and inactivating enzymes and calcium channels in the testes, male reproductive tract and human spermatozoa suggests that vitamin D and calcium may modify male reproductive function. Functional animal models have shown that vitamin D deficiency in male rodents leads to a decrease in successful mating and fewer pregnancies, often caused by impaired sperm motility and poor sperm morphology. Human studies have to a lesser extent validated these findings; however, newer studies suggest a positive effect of vitamin D supplementation on semen quality in cases with vitamin D deficiency, which highlights the need for initiatives to prevent vitamin D deficiency. Calcium channels in male reproductive organs and spermatozoa contribute to the regulation of sperm motility and capacitation, both essential for successful fertilisation, which supports a need to avoid calcium deficiency. Studies have demonstrated that vitamin D, as a regulator of calcium homoeostasis, influences calcium influx in the testis and spermatozoa. Emerging evidence suggests a potential link between vitamin D deficiency and male infertility, although further investigation is needed to establish a definitive causal relationship. Understanding the interplay between vitamin D, calcium and male reproductive health may open new avenues for improving fertility outcomes in men.

Diets and dietary constituents that we consume have a considerable impact on disease risk. Intriguingly these effects may be modulated to some extent by sex. Lack of female representation in nutritional studies as well as a lack of stratification by sex has and continues to limit our understanding of these sex × diet interactions. Here we provide an overview of the current and available literature describing how exposure to certain dietary patterns (Western-style diet, Mediterranean diet, vegetarian/vegan, ketogenic diet) and dietary constituents (dietary fibre, PUFA and plant bioactive) influences disease risk in a sex-specific manner. Interestingly, these sex differences appear to be highly disease-specific. The identification of such sex differences in response to diet stresses the importance of sex stratification in nutritional research.

Menopause is a natural developmental phase that all women go through from their early forties to mid-fifties, marking the transition from the reproductive to the non-reproductive years. This is characterised as the permanent cessation of menses due to progressive ovarian failure. Each woman's experience of the menopause is unique. Biopsychosocial changes occur during this time with some symptoms affecting up to 80 % of women and lasting for 4–5 years from the peri- to post-menopause. Reduced oestrogen may predispose some women to health issues following menopause, such as heart disease, diabetes, stroke and cognitive decline. It is vital to understand how to promote health and well-being to reduce the risk of developing chronic conditions in later life. Increased symptoms and concerns about health during the menopausal transition can be cues to action for some women to actively maintain their health. Menopause represents a window of opportunity to promote health, and to support women to make healthier lifestyle choices, part of the National Institute for Clinical Excellence guidelines for menopause management. Identifying appropriate strategies to change behaviour is less clear. Theories of behaviour change can provide frameworks to gain more insight into the facilitators and barriers to behaviour and can inform the researcher on what needs to change. This information can be used to inform the design, content, implementation and evaluation of a lifestyle intervention. This review paper will explore the impact of menopause on health and well-being generally, and the benefits of designing more effective theory-driven behaviour change interventions for menopause.

Undernutrition in early life remains a significant public health challenge affecting millions of infants and young children globally. Children who are wasted, stunted or underweight are at increased risk of morbidity and mortality. Undernutrition at critical periods also impacts on aspects of neurodevelopment, with longer-term consequences to educational performance and mental health outcomes. Despite consistent evidence highlighting an increased risk of neonatal and infant mortality among boys, a common assumption held across many disciplines is that girls are more vulnerable with respect to early-life exposures. In relation to undernutrition, however, recent evidence indicates the reverse, and in contexts of food insecurity, boys are at increased risk of undernutrition in early life compared to girls, with sex-specific risks for neurodevelopmental deficits. These effects appear independent of social factors that may favour boys, such as gender disparities in infant feeding practices and health-seeking behaviours. The observed vulnerability among boys may therefore be underpinned by biological processes such as differential energy requirements during periods of rapid growth. As boys have greater needs for growth and maintenance, then, in times of nutritional hardship, these needs may not be met resulting in risk of undernutrition and subsequent health consequences. In view of this emerging evidence, a greater understanding of the mechanisms behind this vulnerability among boys is needed and policy considerations to protect boys should be considered. This review will explore sex differences in risk of undernutrition and consider these in the context of existing programmes and policies.

The Olympic Games have grown to be the largest, gender-equal sporting event in the world, and the International Olympic Committee is committed to gender equality in sports encouraging and supporting the promotion of women in sports at all levels and in all structures with a view to implementing the principle of equality of men and women (IOC, 2023). Women competed for the first time at the 1900 Olympic Games in Paris, and the number of women competing has grown exponentially over the last 100 years, so an estimated 5494 female athletes (48 %) competed in the Summer Olympic Games 2021 in Tokyo. Supporting women (alongside men) in achieving optimum performance is crucial, and understanding that there are sex and gender gaps in sports nutrition research is important. One reason for this gap is the historical bias in sports and exercise science research towards male participants. This has led to a poor understanding of the unique physiological and nutritional needs of female athletes. In summary, a balanced approach is crucial to address the nutritional needs of both male and female athletes. Researchers should continue exploring this important area to optimise performance and health for all athletes. The aim of this review is to summarise current sports nutrition literature and highlight research that seeks to understand and address where the gaps are with respect to several key areas in sports nutrition recommendations that can impact advice and practice with both males and females.

CVD is the leading cause of death worldwide, and is commonly associated with modifiable risk factors. Most studies to date examining link between food intake and risk of CVD, have focused on modulation of plasma cholesterol concentrations (total cholesterol (TC), LDL-C). However, recent studies suggest LDL particle size is a more sensitive risk marker for CVD with smaller, dense LDL particles reported as more atherogenic than larger, more buoyant LDL. Although dietary guidelines recommend SFA intake of < 10 % of total energy, this does not consider food source, with recent evidence suggesting differing, sometimes beneficial, lipid responses following consumption of SFA from dairy compared to other food sources. This may be from differences in the physical food matrices, the nutrient content of the foods, and/or how these components interact with each other, described as a ‘dairy matrix effect’. Dietary fat not only raises LDL-C, but also HDL cholesterol (HDL-C), associated with reduced CVD risk. HDL particles are complex emulsions of lipids, proteins and microRNAs that exhibit atheroprotective properties. In addition, HDL particles exhibit a very heterogeneous proteomic composition, dependent on a person’s disease state – with a more pro-inflammatory proteome evident in patients with established CVD. This review will discuss the evidence to date on the importance of the food matrix in modulating response to dietary SFA and impact on CVD risk factors. A focus on potential biomarker properties of lipoprotein particles beyond cholesterol and current use of such biomarkers in human nutrition research will be considered.

The teenage years represent a crucial period of physical and cognitive growth and development with sufficient micronutrient intakes necessary to meet high nutritional requirements. This review examines current micronutrient intakes in teenagers in the Western world in the context of public health implications including the prevalence of inadequate intakes and risk of excessive intakes. Intakes of vitamins A, D, E and C, folate, calcium, iron, magnesium, zinc and potassium in teenagers are low when compared to generally accepted recommendations, while there is little risk of excessive micronutrient intakes based on current dietary patterns. Therefore, strategies should focus on increasing micronutrient intakes in order to decrease the risk of negative impacts resulting from these low intakes. These strategies should be mindful of guidance towards an environmentally sustainable diet whilst ensuring that nutrient intakes in teenagers are not further negatively impacted. In order to identify, implement and monitor the effectiveness of such strategies, intakes of micronutrients should be continually monitored in nationally representative samples of the population for all age groups including this vulnerable cohort of teenagers.

The current food system is unsustainable. It encourages unhealthy food choices, increasing the risk of non-communicable diseases, and has a substantial environmental impact, responsible for around a third of all anthropogenic greenhouse gas emissions. Improving both public and planetary health will require dietary change. To promote this transition, it is crucial to understand how consumers conceptualise healthy and sustainable eating. The aim of this review was to examine how adults from high-income countries interpret healthy and sustainable eating, with a specific focus on Ireland and the UK. As healthy eating and sustainable eating are often conceptualised as distinctive constructs, we explored each of these separately before examining how consumers perceive them together. Most consumers have a reasonable understanding of what constitutes a healthy diet, with many echoing aspects consistent with dietary guidelines. However, consumers perceptions of healthy eating often extend beyond these health-centric recommendations, incorporating concepts such as the pleasure of eating and supporting mental well-being. Sustainable eating, on the other hand, is less well understood. Most consumers overemphasise the importance of eating local, organic food and reducing packaging and underestimate or are unaware of the environmental impact of red meat consumption. These findings provide a clear opportunity to improve public awareness of healthy and sustainable diets. Moreover, they emphasise the need to promote the synergies between healthy and sustainable dietary practices. However, knowledge alone will not be enough to change behaviour. Future interventions should also seek to overcome consumers competing dietary priorities and create system-wide changes.

Endogenous oestrogens regulate essential functions to include menstrual cycles, energy balance, adipose tissue distribution, pancreatic β-cell function, insulin sensitivity and lipid homeostasis. Oestrogens are a family of hormones which include oestradiol (E2), oestrone (E1) and oestriol (E3). Oestrogens function by binding and activating oestrogen receptors (ERs). Phytoestrogens are plant-derived compounds which exhibit oestrogenic-like activity and can bind to ERs. Phytoestrogens exert potential oestrogenic-like benefits; however, their effects are context-dependent and require cautious consideration regarding generalised health benefits. Xenoestrogens are synthetic compounds which have been determined to disrupt endocrine function through binding to ERs. Xenoestrogens enter the body through various routes and given their chemical structure they can accumulate, posing long-term health risks. Xenoestrogens interfere with endogenous oestrogens and their functions contributing to conditions like cancer, infertility, and metabolic disorders. Understanding the interplay between endogenous and exogenous oestrogens is critical in order to determine their potential health consequences and requires further investigation. This manuscript provides a summary of the role endogenous oestrogens have in regulating metabolic functions. Additionally, we discuss the impact phytoestrogens and synthetic xenoestrogens have on biological systems across various life stages. We highlight their mechanisms of action, potential benefits, risks and discuss the need for further research to bridge gaps in understanding and mitigate exposure-related health risks.

There is significant evidence that an unhealthy diet greatly increases the risk of complications during pregnancy and predisposes offspring to metabolic dysfunction and obesity. While fat intake is typically associated with the onset of obesity and its comorbidities, there is increasing evidence linking sugar, particularly high fructose corn syrup, to the global rise in obesity rates. Furthermore, the detrimental effects of added sugar intake during pregnancy on mother and child have been clearly outlined. Guidelines advising pregnant women to avoid food and beverages with high fat and sugar have led to an increase in consumption of ‘diet’ or ‘light’ options. Examination of some human birth cohort studies shows that heavy consumption (at least one beverage a day) of non-nutritive sweetener (NNS) containing beverages has been associated with increased risk of preterm birth and increased weight/BMI in male offspring independent of maternal weight, which appears to be offset by breastfeeding for 6 months. Rodent models have shown that NNS exposure during pregnancy can impact maternal metabolic health, adipose tissue function, gut microbiome profiles and taste preference. However, the mechanisms underlying these effects are multifaceted and further research, particularly in a translational setting is required to fully understand the effects of NNS on maternal and infant health during pregnancy. Therefore, this review examines maternal sweetener intakes and their influence on fertility, maternal health outcomes and offspring outcomes in human cohort studies and rodent models.