Environmental impacts of food systems have stimulated research to examine how to create healthy diets that will be more sustainable while meeting nutrient requirements. Increasing compliance with existing food-based dietary guidelines in most jurisdictions could be a first step to improve health and reduce environmental impact. MyPlanetDiet was an all-Ireland 12-week randomised controlled trial designed to inform sustainable healthy dietary guidelines. Healthy adults (n 355) aged 18–64 years with moderate-to-high greenhouse gas emitting (GHGE) diets were recruited from three study sites on the island of Ireland. The aim of this research is to assess the relationship between dietary intakes, diet-related environmental impacts and metabolic health using baseline data collected during the MyPlanetDiet study. Dietary assessments collected using Foodbook24 were used to calculate diet-related GHGE, adherence to healthy eating guidelines (HEG) and healthy eating index (HEI) score. Anthropometrics and metabolic health markers (e.g. lipids, glucose and insulin) were included. Overall HEG adherence was low, with 43 % meeting zero or one HEG food group recommendations. Adherence to 4 + HEG food group targets was associated with 31 % lower diet-related GHGE compared with those with lowest adherence. Higher HEG adherence was associated with lower BMI and waist circumference and higher HEI scores. While our findings suggest HEG adherence is associated with positive health and environmental impacts, substantial behaviour change will be needed to meet existing HEG. Further research is needed to assess response and acceptability to HEG. However, adherence to HEG may be an important first step to reducing the environmental impact of food consumption.

Globally, diet quality is poor, with populations failing to achieve national dietary guidelines. Such failure has been consistently linked with malnutrition and poorer health outcomes. In addition to the impact of diet on health outcomes, it is now accepted that what we eat, and the resulting food system, has significant environmental or planetary health impacts. Changes are required to our food systems to reduce these impacts and mitigate the impact of climate change on our food supply. Given the complexity of the interactions between climate change, food and health, and the different actors and drivers that influence these, a systems-thinking approach to capture such complexity is essential. Such an approach will help address the challenges set by the UN 2030 Agenda for sustainable development in the form of the sustainable development goals (SDG). Progress against SDG has been challenging, with an ultimate target of 2030. While the scientific uncertainties regarding diet and public and planetary health need to be addressed, equal attention needs to be paid to the structures and systems, as there is a need for multi-level, coherent and sustained structural interventions and policies across the full food system/supply chain to effect behaviour change. Such systems-level change must always keep nutritional status, including impact on micronutrient status, in mind. However, benefits to both population and environmental health could be expected from achieving dietary behaviour change towards more sustainable diets.

An increasing number of food-based recommendations promote a plant-based diet to address health concerns and environmental sustainability in global food systems. As the main sources of iodine in many countries are fish, eggs and dairy products, it is unclear whether plant-based diets, such as the EAT-Lancet reference diet, would provide sufficient iodine. This is important as iodine, through the thyroid hormones, is required for growth and brain development; adequate iodine intake is especially important before, and during, pregnancy. In this narrative review, we evaluated the current literature and estimated iodine provision from the EAT-Lancet reference diet. There is evidence that those following a strict plant-based diet, such as vegans, cannot reach the recommended iodine intake from food alone and are reliant on iodine supplements. Using the EAT-Lancet reference diet intake recommendations in combination with iodine values from UK food tables, we calculated that the diet would provide 128 μg/d (85 % of the adult recommendation of 150 μg/d and 51–64 % of the pregnancy recommendation of 200–250 μg/d). However, if milk is replaced with unfortified plant-based alternatives, total iodine provision would be just 54 μg/d (34 % and 22–27 % of the recommendations for adults and pregnancy, respectively). Plant-based dietary recommendations might place consumers at risk of iodine deficiency in countries without a fortification programme and where animal products provide the majority of iodine intake, such as the UK and Norway. It is essential that those following a predominantly plant-based diet are given appropriate dietary advice to ensure adequate iodine intake.

Selenium (Se) is an essential trace element which has an important role as a constituent of seleno-proteins involved in various physiological processes. Previous research in Irish adults suggests that intakes of this important nutrient are suboptimal. The aim of the present study was to estimate the current intakes and major food sources of Se by Irish adults. Mean daily intakes (MDIs) of Se were calculated using data from the National Adult Nutrition Survey which involved 1500 Irish adults aged 18–90 years. The Se content of foods and drinks consumed over a 4-d period was determined using data from the Irish Total Diet Study (TDS). Adequacy of Se intakes was assessed by calculating the proportion of the population with intakes below the adequate intake (AI) of 70 μg/d and lower reference nutrient intake of 40 μg/d (LRNI). The MDI of Se in the total population was 71⋅7 μg/d, with significantly higher intakes reported in men (80⋅2 μg/d) compared with women (63⋅4 μg/d, P < 0⋅01). Meat and meat products were the major contributing food group to Se intakes for both men (37 %) and women (31 %). Overall, 47 % of the population were not meeting the recommended AI, while 4 % of the total population were not meeting the LRNI. Although the average intake of Se is above the AI, a significant proportion of the population is not meeting this recommendation and continued monitoring of Se intakes is necessary, particularly by at-risk groups and also in the context of sustainability.

Milk, dairy products, and fish are the main sources of iodine in the UK. Plant-based products are increasingly popular, especially with young women, which may affect iodine intake as they are naturally low in iodine; this is concerning as iodine is required for fetal brain development. We, aimed to (i) assess the iodine fortification of products sold as alternatives to milk, yoghurt, cheese and fish through a cross-sectional survey of UK retail outlets in 2020, and (ii) model the impact of substitution with such products on iodine intake, using portion-based scenarios. We identified 300 products, including plant-based alternatives to: (i) milk (n 146); (ii) yoghurt (n 76); (iii) cheese (n 67) and (iv) fish (n 11). After excluding organic products (n 48), which cannot be fortified, only 28 % (n 29) of milk alternatives and 6 % (n 4) of yoghurt alternatives were fortified with iodine, compared with 88 % (n 92) and 73 % (n 51), respectively, with Ca. No cheese alternative was fortified with iodine, but 55 % were fortified with Ca. None of the fish alternatives were iodine fortified. Substitution of three portions of dairy product (milk/yoghurt/cheese) per day with unfortified alternatives would reduce the iodine provided by 97·9 % (124 v. 2·6 µg) and substantially reduce the contribution to the adult intake recommendation (150 µg/d; 83 v. 1·8 %). Our study highlights that the majority of plant-based alternatives are not iodine fortified and that the use of unfortified alternatives put consumers at risk of iodine deficiency.

Older adults (≥65 years) are the fastest growing population group. Thus, ensuring nutritional well-being of the ‘over-65s’ to optimise health is critically important. Older adults represent a diverse population – some are fit and healthy, others are frail and many live with chronic conditions. Up to 78% of older Irish adults living independently are overweight or obese. The present paper describes how these issues were accommodated into the development of food-based dietary guidelines for older adults living independently in Ireland. Food-based dietary guidelines previously established for the general adult population served as the basis for developing more specific recommendations appropriate for older adults. Published international reports were used to update nutrient intake goals for older adults, and available Irish data on dietary intakes and nutritional status biomarkers were explored from a population-based study (the National Adult Nutrition Survey; NANS) and two longitudinal cohorts: the Trinity-Ulster and Department of Agriculture (TUDA) and the Irish Longitudinal Study on Ageing (TILDA) studies. Nutrients of public health concern were identified for further examination. While most nutrient intake goals were similar to those for the general adult population, other aspects were identified where nutritional concerns of ageing require more specific food-based dietary guidelines. These include, a more protein-dense diet using high-quality protein foods to preserve muscle mass; weight maintenance in overweight or obese older adults with no health issues and, where weight-loss is required, that lean tissue is preserved; the promotion of fortified foods, particularly as a bioavailable source of B vitamins and the need for vitamin D supplementation.

Currently, there is considerable emphasis on the relationship between dietary sugar consumption and various health outcomes, with some countries and regions implementing national sugar reduction campaigns. This has resulted in significant efforts to quantify dietary sugar intakes, to agree on terms to describe dietary sugars and to establish associated recommendations. However, this information is infrequently collated on a global basis and in a regularised manner. The present review provides context regarding sugar definitions and recommendations. It provides a global review of the available data regarding dietary sugar intake, considering forms such as total, free and added sugars. A comprehensive breakdown of intakes is provided by age group, country and sugar form. This analysis shows that free sugar intakes as a percentage of total energy (%E) are the highest for children and adolescents (12–14%E) and the lowest for older adults (8%E). This trend across lifecycle stages has also been observed for added sugars. The available data also suggest that, while some reductions in sugar intake are observed in a few individual studies, overall intakes of free/added sugars remain above recommendations. However, any wider conclusions are hampered by a lack of detailed high-quality data on sugar intake, especially in developing countries. Furthermore, there is a need for harmonisation of terms describing sugars (ideally driven by public health objectives) and for collaborative efforts to ensure that the most up-to-date food composition data are used to underpin recommendations and any estimates of intake or modelling scenarios.

Cereals and cereal products have a long history of use by humans. Recently, there have been some discussions regarding level of processing as a descriptor to define food products, including cereal-based foods. This has led to a somewhat emotional debate on food processing. Given the widespread inclusion of cereals in the diet, this review highlights the history of cereal processing as well as their consumption by humans. It provides an evidence-based discussion on their production, contribution to human nutrition, benefits and disadvantages. The present review illustrates the impact of processing on nutrients, as well as non-nutrients specifically in bread and ready-to-eat breakfast cereals (RTEC), two cereal-based foods which are widely consumed and integral parts of food-based dietary guidelines globally. As a category, most cereals must be processed in some way to enable consumption by humans as we are not equipped to survive exclusively on raw grains. Even thousands of years ago, the processing of cereals was a common practice by humans, turning raw grains into palatable, safe and nutritious foods. Modern processes for cereal-based products are efficient in providing safe and good-quality products to satisfy population needs, as well as helping to meet consumer expectations by providing a range of foods that allows for a varied and balanced diet. Today, RTEC and bread make significant contributions to dietary energy and nutrient requirements and underpin food-based dietary guidance globally. They have been positively linked with intake of dietary fibre, vitamins and minerals, especially when consumed as whole grain.

Meta-analyses of epidemiological data report that adults who carry a common polymorphism, the MTHFR 677C→T, in the gene encoding the folate-metabolising enzyme methylenetetrahydrofolate reductase (MTHFR) have a 40% increased risk of CVD and an 87% increased risk of hypertension. Riboflavin (vitamin B2), in its co-enzymatic form flavin adenine nucleotide (FAD), is required as a co-factor by MTHFR and previous trials in hypertensive patients have shown a blood pressure lowering response to riboflavin supplementation that is specific to individuals homozygous for this polymorphism (TT genotype). Low folate status is commonly reported in adults with the TT genotype however the effect of this genetic variant on riboflavin status has not previously been investigated. The aim of this study, therefore, was to investigate dietary intake and biomarker status of riboflavin by MTHFR genotype in Irish adults using data from the National Adult Nutrition Survey (2008–2010) (www.iuna.net).

A 4-day semi-weighed food record was used to collect food and beverage intake data from a representative sample of 1500 Irish adults (18–90 years). Dietary intake data were analysed using WISP© based on UK food composition tables (modified to include recipes of composite dishes, nutritional supplements, fortified foods and generic Irish foods that were commonly consumed). Usual intakes were calculated via the NCI-method using SAS© Enterprise Guide. Blood samples (n = 1126) were collected by venepuncture by a trained professional and were processed and analysed using standard operating procedures. Biomarker status of riboflavin was determined by erthyrocyte gluthathione reductase activation coefficient (EGRac), a functional assay that measures the activity of the enzyme glutathione reductase before and after in vitro activation with its prosthetic group FAD; a lower value indicates better status.

It was found that 12% of the population had the TT genotype. As expected, there was no significant difference in riboflavin intake across the genotype (CC, CT or TT) groups. Similarly, no significant genotype differences in riboflavin status (EGRac) were observed (1.36 vs 1.37 vs 1.38 respectively). Overall, 61% of the total population had EGRac values > 1.3, indicative of low/deficient status with no significant difference observed between the genotype groups (60%,61% and 61%, respectively).

These data suggest that riboflavin status is not influenced by the C677T polymorphism in MTHFR in this cohort of nationally representative Irish adults. Further research is needed to see the impact of riboflavin status on blood pressure across the genotype groups in this nationally representative cohort of Irish adults.

Recent evidence suggests that menaquinones (Vitamin K2) may be important for both bone health and cardiovascular health. With the exception of menaquinone-4 which is formed from the tissue specific conversion of phylloquinone or menadione, menaquinones are synthesized by bacteria. They are typically found in foods of animal origin such as meat, dairy and fermented foods and may account for up to 25% of total vitamin K intake. There are few data available on menaquinone intakes in population groups due to lack of available composition data. The Irish food composition database however has recently been updated to include data on menaquinones. Therefore, the aim of this study was to use these data to estimate the intakes and key dietary sources of menaquinones (menaquinone-4 & menaquinone-5–10) in the Irish population.

Analyses included data from four nationally representative surveys of the Irish population; The National Pre-School Nutrition Survey (1–4y; 2010–2011), the National Children's Food Survey (5–12y; 2003–2004), the National Teens’ Food Survey (13–17y; 2005–2006) and the National Adult Nutrition Survey (18–90y; 2008–2010) (www.iuna.net). For all of the surveys, food and beverage intake data (including supplements) were collected using food records and quantified using food scales, photographic atlases, household measures and standard portion sizes. Mean daily intakes of menaquinone-4 and menaquinone-5–10 were estimated using UK food composition tables and analytical values from published papers. The percent contribution of food groups to menaquinone intake was calculated by the mean proportion method (which provides information about the sources that are contributing to the nutrient intake ‘per person’). Statistical analyses were carried out using SPSS© V22.

Mean intakes of menaquinone-4 ranged from 8–12μg/d and 10–14μg/d in children aged 1–17 years and adults aged 18–90 years, respectively. Mean combined intakes of menaquinone-5–10 ranged from 32–43μg/d and 32–50μg/d in children aged 1–17 years and adults aged 18–90 years, respectively. ‘Meat & meat products’ were the top contributor of menaquinone-4 (50–66%) intakes across all population groups followed by ‘milks’ (9–25%). ‘Meat & meat products’ (44–61%) and ‘cheeses’ (21–37%) were important contributors to menaquinone-5–10 intakes across all population groups examined.

This study is the first of its kind to report the intakes and sources of menaquinones in the Irish population. ‘Meat & meat products’, ‘cheeses’ and ‘milks’ are important contributors to intakes of menaquinones in the Irish diet. Further research is required to fully understand the role of the menaquinones in human health.

Excess body fat is associated with the production of pro-inflammatory molecules from dysfunctional adipose tissue resulting in systemic inflammation. Inflammation stimulates expression of the iron regulatory hormone hepcidin, resulting in elevated serum ferritin and iron overload in metabolic tissues. Hepcidin driven iron maldistribution may be implicated in the development of metabolic diseases such as Type 2 diabetes and CVD. The aim of this study was to investigate the effect of body fat and the associated inflammation on markers of iron homeostasis.

Analyses were based on data from the cross-sectional National Adult Nutrition Survey (2008–2010) (www.iuna.net). Percentage body fat (BF%) of participants (n = 1211) was measured by a Tanita BC420MA device. Participants were classified as healthy, overweight or obese based on age and gender-specific BF% ranges. Serum ferritin and serum hepcidin were measured using immunoturbidimetric immunoassays. ANCOVA with Bonferroni post hoc (p < 0.05) was used to compare anthropometric parameters, biochemical markers of iron status and inflammation and nutrient intakes between BF% groups. Predictors of serum hepcidin and serum ferritin were determined using linear regression analysis.

In the population 42% were classified as healthy, 33% as overfat and 25% as obese. Serum hepcidin was significantly elevated in obese participants (8.42ng/ml ± 4.2) compared to their healthy counterparts (6.49ng/ml ± 3.9)(p < 0.001). Significantly higher serum ferritin was observed in obese (223ng/ml ± 170) and overfat males (166ng/ml ± 120) compared to healthy males (135ng/ml ± 91)(p < 0.001). A significant percentage of overweight (20%) and obese (32%) participants were at severe risk of iron overload compared to healthy participants (8%)(p < 0.001). No significant differences in dietary iron intakes were observed between BF% groups. Linear regression analysis indicated that BF% was a significant (p < 0.001) predictor of hepcidin in males (β = 0.327) and females (β = 0.226). IL-6 (β = 0.317,p < 0.001) and TNFα (β = 0.229,p < 0.001) were the strongest inflammatory predictors of hepcidin in females only. In males, leptin was a positive predictor (β = 0.159,p = 0.003) of hepcidin, while adiponectin displayed a negative predictive relationship (β = -0.145,p = 0.001)

Our results indicate that excessive adiposity is associated with elevated serum ferritin and hepcidin independent of dietary intake. Cytokines are a potential driver of hepcidin in females, with adipose-derived hormones seeming to have the greater effect in males. These results may help to elucidate the relationship between obesity and dysregulated iron metabolism. Further research is required to investigate the metabolic effects of hepcidin-induced iron overload in those with excess body fat.

Breakfast is often referred to as ‘the most important meal of the day’ and is consumed after the longest postprandial fast (an overnight fast). Breakfast consumption has been positively linked to many health benefits and has been shown in many studies to be associated with a better diet quality. The aim of this study was to characterise breakfast in Irish adults and to investigate the contribution of breakfast to overall daily nutrient intake.

Analyses were based on the National Adult Nutrition Survey (NANS) (2008–2010) (www.iuna.net). A 4 day semi-weighed food record was used to collect food and beverage intake data from a nationally representative sample of 1500 adults in the Republic of Ireland. Nutrient intakes were estimated using WISP© based on UK and Irish food composition data. Breakfast was subjectively defined by the participant and reported in the food diary. In line with recommendations on breakfast studies, this study confined analyses to nutrients derived from breakfast foods and not nutritional supplements. Usual intakes of energy and selected nutrients (from breakfast foods only and total diet (including nutritional supplements)) were calculated via the NCI-method using SAS© Enterprise Guide.

Breakfast was consumed on at least one recording day by 99% of participants with an uptake of 93% of potential breakfast occasions. The mean (SD) energy intake at breakfast was 365 (162) kcal, contributing on average 19% to overall daily energy intake. Energy intake from breakfast comprised of 56% carbohydrate, 14% fat and 29% protein. The most frequently consumed foods at breakfast included breakfast cereals, white/brown/wholemeal breads and rolls, butters and fat spreads, jams and marmalades, fruits, eggs, yogurts and some meats. The most frequently consumed beverages included teas, coffees, ‘fruit juices & smoothies’, waters and milk (in teas/coffees, with cereals and as a beverage). The contribution of breakfast to total daily nutrient intakes was 25% for carbohydrate, 16% for fat and 16% for protein. Breakfast also contributed to total daily intakes of dietary fibre (22%), total sugars (28%), saturated fat (18%), B-vitamins (20–32%), vitamins C (23%), D (24%), E (19%) calcium (28%), iron (26%) and sodium (18%).

Breakfast was widely consumed among Irish adults and was typically a nutrient dense meal which contributed significantly to total dietary intakes of a number of important macro- and micro- nutrients but also contributed to total sugars and relatively small proportions of total fat, saturated fat, and sodium.

A diet rich in plant-based foods with fewer animal products may offer improved health and environmental benefits. There is little consensus on the definition for a plant-based diet in the literature with some defining it as one rich in vegetables, legumes, fruits, wholegrains, nuts and seeds, excluding animal foods and with heavy restrictions on processed foods. Other definitions make no reference to the inclusion/exclusion of processed foods and refer only to the exclusion of all animal foods from the total diet. This study aimed to examine the nutritional quality of the Irish diet using each of these plant-based diet definitions.

A 4-day semi-weighed food record collected food intake data from 1500 Irish adults (18–90y) in the National Adult Nutrition Survey (NANS). Nutrient intake was analysed using WISP© based on UK and Irish food composition databases. All foods and beverages consumed in the NANS were categorised (included/excluded) into the two definitions; 1.plant-based component of the diet and 2.total diet excluding all animal components. The plant-based component included vegetables, legumes, fruits, wholegrains, nuts and seeds and excluded all animal foods and processed foods. The second categorisation included all non-animal foods regardless of processing. Nutritional quality was assessed by estimating energy-adjusted intakes of macronutrients, saturated fat, free sugars, dietary fibre and sodium. Stastical analysis was conducted using SPSS© v24.

The plant-based component of the diet provided 309 ± 214kcal/d (1.3 ± 0.9MJ/d) comprising of 68% carbohydrate, 20% fat and 12% protein. Mean intakes of saturated fat and free sugars from the plant-based component of the diet were 5% of energy (%E) and 1%E, respectively. Mean intakes of dietary fibre and sodium were 70g/10MJ and 1855mg/10MJ, respectively.

Allowing for inclusion of processed foods, mean energy intake from the total diet excluding all animal foods was 1051 ± 411kcal/d (4.4 ± 1.7MJ/d) comprising of 66% carbohydrate, 23% fat and 10% protein. Mean intakes of saturated fat and free sugars were 7%E and 14%E, respectively. Mean intakes of dietary fibre and sodium were 40g/10MJ and 2642mg/10MJ, respectively.

Overall, the macronutrient profile of the plant-based component of the diet and the total diet excluding animal foods were similar. However, the plant-based component of the diet was of higher nutritional quality; providing lower intakes of saturated fat, free sugar and sodium and higher intakes of dietary fibre compared to the total diet excluding animal foods. This study highlights the variability in nutritional quality between different definitions of plant based-diets.