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.