The adoption of dietary patterns emphasising higher intakes of plant foods and lower intakes of animal foods (plant-based diets, PBDs), continue to rise worldwide. PBDs have been associated with a lower risk of cardiovascular morbidity and mortality as well as major risk factors such as overweight/obesity and type 2 diabetes. Evidence regarding the dietary profile and disease risk associated with various PBDs in comparison to traditional meat-eating diets are scarce within the Australian population. The aim of this study is to investigate the 5-year and 10-year risk of developing cardiovascular disease (CVD) among Australians habitually following various PBDs compared to a regular meat diet (RMD). The Plant-based Diet (PBD) Study is a cross-sectional study consisting of healthy adults between aged 30-75 years from the Hunter Region (NSW) between 2021-2023. A validated FFQ was used to assess eligibility and categorise individuals who were habitually consuming one of five dietary patterns for at least 6 months into the following groups: vegan (nil animal products), lacto-vegetarian (LOV, including eggs and dairy), pesco-vegetarian (PV, including seafood with/without dairy and eggs), semi-vegetarian (SV, minimal consumption of animal products) or RMDs (including animal meat daily or multiple times/day)(1). 5-year and 10-year CVD risk was quantified using the Framingham Risk Equation(2) and the Australian Absolute CVD risk calculator, respectively. CVD risk and other quantitative measures was compared using One-way ANOVA or Kruskal Wallis, and Chi-square or Fisher’s Exact for qualitative data. Directed acyclic graphs displayed confounding variables and mediators and a regression model was used to adjust for these. A total of 240 participants (median age 55(16), 77.5% female) with 48 participants in each group showed a significant difference in predicted 5-year risk of CVD (P<0.05), however 10-year risk did not significantly differ across groups. 5-year CVD risk was significantly lower in the vegan group (1%) compared to the RMD, SV, PV, and LOV diet groups (all 2%). In comparison to a vegan diet, crude association showed those consuming a RMD had a 2.4% (95% CI 0.7, 4.1) higher 5-year risk of developing CVD, followed by 1.7% in LOV (95% CI 0.6, 2.9), 1.8% in PV (95% CI 0.5, 3), and 1.1% in SV (95% CI 0.2, 2.1). Significance was lost after adjusting for confounders such as age, gender, smoking status, alcohol intake, physical activity levels and BMI. This is the first study to purposefully sample Australians habitually following PBD, presenting novel population-based evidence for CVD risk. These findings suggest more restrictive PBDs such as vegan diets when compared to RMD may lead to lower CVD risk, however population-based longitudinal studies primary investigating the development of CVDs in the context of PBDs are warranted.

The gut microbiome is a key element for health preservation and disease prevention. Nevertheless, defining a healthy gut microbiome is complex since it is modulated by several factors, such as host genetics, sex, age, geographical zone, drug use, and, especially, diet. Although a healthy diet has proven to increase microbial alpha and beta diversity and to promote the proliferation of health-related bacteria, considering the current environmental and nutritional crisis, such as climate change, water shortage, loss of diversity, and the obesity pandemic, it should be highlighted that a healthy diet is not always sustainable. Sustainable diets are dietary patterns that promote all dimensions of people’s health and well-being while exerting low pressure on the environment, and being accessible, affordable, safe, equitable, and culturally acceptable. Examples of diets that tend to be sustainable are the Planetary Health Diet of the EAT-Lancet Commission or territorial diets such as the Mediterranean and the Traditional Mexican diet (milpa diet), adapted to specific contexts. These diets are principally plant-based but include small or moderate amounts of animal-based foods. Characterising the effects of sustainable diets on gut microbiota is urgent to ensure that the benefits for human health are aligned with environmental preservation and respect the sociocultural aspects of individuals.

Despite evidence for favourable health outcomes associated with plant-based diets, a database containing the plant and animal content of all foods eaten is required to undertake a reliable assessment of plant-based diets within a population. This study aimed to expand an existing Australian food database to include the plant and animal content of all whole foods, beverages, multi-ingredient products and mixed dishes. Twenty-three plant- and animal-based food group classifications were first defined. The food servings per 100 g of each product were then systematically calculated using either a recipe-based approach, a food label-based approach, estimates based on similar products or online recipes. Overall, 4687 (83·5 %) foods and beverages were identified as plant or plant-containing products, and 3701 (65·9 %) were animal or animal-containing products. Results highlighted the versatility of plant and animal ingredients as they were found in various foods across many food categories, including savoury and sweet foods, as well as discretionary and core foods. For example, over 97 % of animal fat-containing foods were found in major food groups outside the AUSNUT 2011–2013 ‘fats and oils’ group. Surprisingly, fruits, nuts and seeds were present in a greater percentage of discretionary products than in core foods and beverages. This article describes a systematic approach that is suitable for the development of other novel food databases. This database allows more accurate quantitative estimates of plant and animal intakes, which is significant for future epidemiological and clinical research aiming to investigate plant-based diets and their related health outcomes.

Dietary behaviours and the food systems in which they occur have a significant impact on climate change. The 2022 Intergovernmental Panel on Climate Change (IPCC) reports and other major climate reports have identified population-level dietary shifts towards balanced, sustainable healthy diets as an important mitigation (i.e. prevention) solution for climate change. Thus, public health nutrition researchers and practitioners have a crucial role to play in combatting the climate crisis. They have the content expertise, interdisciplinary training and technical skills needed to facilitate wide-scale dietary behaviour changes at multiple levels of influence and ultimately improve both human and planetary health. This commentary article: (i) summarises how dietary behaviours and food systems contribute to climate change, with a particular focus on high-income countries; (ii) reviews food-system-related climate change mitigation solutions most relevant to public health nutrition researchers and practitioners; and (iii) identifies key gaps in the literature and future research directions for the field.

Plant-based (PB) diets are associated with good health and are also recommended for environmental sustainability. The present review aimed to summarise the definitions of PB diets globally and to investigate the nutritional role of PB diets in adults. This review found that there is a wide range of PB definitions ranging from the traditional vegetarian diets (including vegan) to semi-vegetarian/flexitarian diets. Furthermore, other diets which were originally developed due to their associations with positive health outcomes, such as the portfolio, Mediterranean-style, DASH, healthy US-style, planetary health and Nordic-style diets, have been encompassed in PB definitions due to their emphasis on certain PB components. This review has highlighted that those consuming a PB diet are more likely to meet recommended intakes for carbohydrate, dietary fibre and vitamin E and are less likely to meet recommendations for protein, vitamin B12 and iodine compared to omnivores. Regardless of consumer type, neither PB consumers nor omnivores met recommendations for intakes of vitamin D, calcium and sodium. While intakes of protein, n-3, iron and zinc were generally sufficient from the PB diet, it is important to acknowledge the lower bioavailability of these nutrients from PB foods compared to animal-derived products. As dietary patterns shift towards a more PB diet, there is a need for further studies to investigate the role of PB diets for nutritional adequacy and status in populations currently accustomed to consuming a primarily omnivorous diet.

This study investigated the association between the different types of plant-based diets and dyslipidaemia in Korean adults using data from the nationally representative sample. Using the 2012–2016 Korea National Health and Nutrition Survey data, a total of 14 167 adults (≥19 years old) participated in this study. Dietary intake was assessed by a semi-quantitative FFQ. Three different plant-based diet indices (overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), unhealthful plant-based diet index (uPDI)), were calculated. Dyslipidaemia and its components (hypertriacylglycerolaemia, hypercholesterolaemia, low HDL-cholesterol, high LDL-cholesterol, use of anti-hyperlipidaemia agent) were measured. Multivariable logistic regression analysis was used to examine the associations between plant-based diet and dyslipidaemia and individual lipid disorders. Totally, 47% of overall population had dyslipidaemia. Individual in the highest quintile of uPDI had 22% greater odds of dyslipidaemia (95 % CI 1·05, 1·41) and 48 % higher odds of hypertriacylglycerolaemia (95 % CI 1·21, 1·81) and 16% higher odds of low HDL-cholesterol (OR: 1·16, 95 % CI 1·00, 1·35) than those in the lowest quintile of uPDI. PDI was associated with 16 % higher odds of low HDL-cholesterol, and hPDI was associated with 25% lower odds of high LDL-cholesterol. However, neither PDI nor hPDI was significantly associated with the prevalence of dyslipidaemia. Greater adherence to unhealthful plant-based diets was associated with greater odds of the dyslipidaemia and its components suggesting the importance of the quality of plant-based diet in South Korean adults for dyslipidaemia prevention.

Fasting has been a practice among followers of different religions for many years. Christian Orthodox Church (COC) fasting is a periodic vegetarian-type diet in which seafood and snails are allowed on most fasting days. The present scoping review aimed to present available data regarding the benefits of COC fasting on metabolic syndrome (MetS) risk factors. Databases were searched for available studies. Twenty publications, with a total of 1226 fasting participants, provided data on the effects on different variables of MetS, including blood pressure, blood lipids and anthropometric measurements. Fasters’ diet is characterised by low saturated and trans fat intake, high complex carbohydrate and fibre consumption, due to permissible foods. COC fasting has no deficiency in essential amino acid intake since seafood and snails are allowed on fasting days. Fasters have healthier blood lipid profiles during and after COC fasting periods, and total cholesterol, LDL-cholesterol, systolic blood pressure, body weight and BMI are reduced after a fasting period. Due to restricted or forbidden intake of specific foods during the COC fasting periods, one might expect that fasters have reduced intake of macro- and micronutrients, but as shown in the available literature, there are no deficiencies. Future research on COC fasting is needed in areas not investigated at all, like MetS, before reaching definite conclusions.

No studies have investigated the associations between established plant-based diet indices and the metabolic syndrome (MetS). We evaluated the associations between an overall plant-based diet index (PDI), healthy PDI (hPDI), unhealthy PDI (uPDI) and the MetS in a nationally representative sample using data from 14 450 Korean adults (≥19 years) in the Korea National Health and Nutrition Examination Survey 2012–2016. Dietary intakes were assessed by a semi-quantitative FFQ. In the PDI, all plant foods received positive scores. In the hPDI, only healthy plant foods received positive scores. In the uPDI, only unhealthy plant foods received positive scores. All indices reverse scored animal food intake. Multivariable logistic regression models were used to examine the associations between three PDI and the MetS by sex, adjusting for potential risk factors. A total of 23·3 % of Korean adults had the MetS. In the overall study population, individuals in the highest quintile of uPDI had greater odds (OR 1·54, 95 % CI 1·28, 1·86, Ptrend < 0·001) of the MetS than those in the lowest quintile. Higher uPDI score was associated with higher odds of hypertriacylglycerolaemia in men and abdominal obesity, high fasting glucose and hypertriacylglycerolaemia in women. No significant associations were observed between PDI, hPDI and the MetS. Greater adherence to unhealthy plant-based diets was associated with greater odds of the MetS and its components suggesting the importance of the quality of plant-based diet in South Korean adults. Sex differences may be considered when recommending plant-based diets for the prevention and management of metabolic diseases.

Plant-based diets are considered healthier than many omnivorous diets. However, it is unclear that restriction of animal products necessarily motivates increased consumption of nutrient- and fibre-rich plant-based foods as opposed to energy-dense but nutrient-poor plant-based foods containing refined grains and added sugars and fats. The present study examined FFQ and food record data from ninety-nine individuals in the USA with varying degrees of adherence to the Orthodox Christian tradition of restricting meat, dairy and egg (MDE) products for 48 d prior to Easter to investigate whether restricting MDE products in the absence of explicit nutritional guidance would lead to increased consumption of healthy plant-based foods and greater likelihood of meeting dietary recommendations. Multiple linear regression models assessed changes in major food groups, energy and nutrients in relation to the degree of reduction in MDE consumption. Logistic regression analyses tested the odds of meeting 2015–2020 Dietary Guidelines for Americans on plant-based foods in relation to MDE restriction. Each serving reduction in MDE products was associated with small (approximately 0·1–0·7 serving) increases in legumes, soya products and nuts/seeds (all P values < 0·005). MDE restriction was not associated with higher odds of meeting recommendations on vegetable, fruit or whole-grain intake. Consumption of refined grains and added sugars did not change in relation to MDE restriction but remained above recommended thresholds, on average. These findings demonstrate that a reduction of MDE products for spiritual purposes may result in increases in some nutrient-rich plant-based foods but may not uniformly lead to a healthier dietary composition.

Evidence suggests a relationship between polyphenol intake and health benefits. Polyphenol intake among a large US cohort with diverse dietary practices ranging from meatless to omnivorous diets has not been previously evaluated. The primary aim of this study was to compare polyphenol intakes of several vegetarian and non-vegetarian dietary patterns and to assess phenolic intake by food source. To characterise dietary intake, a FFQ was administered to 77 441 participants of the Adventist Health Study-2. Dietary patterns were defined based on the absence of animal food consumption as vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian and non-vegetarian. Polyphenol intakes were calculated based on chromatography-derived polyphenol content data of foods from Phenol-Explorer, US Department of Agriculture databases and relevant literature. Results revealed a mean unadjusted total polyphenol intake of 801 (sd 356) mg/d, and the main foods contributing to polyphenol intakes were coffee, fruits and fruit juices. Total polyphenol intake differed significantly between dietary patterns, with phenolic acids from coffee contributing the greatest variation. The dominant classes and sources of dietary polyphenols differed between vegetarian and non-vegetarian diets. Flavonoid intake was the highest among pesco-vegetarians, and phenolic acid intake was the highest among non-vegetarians. In addition, coffee consumers appeared to have a different dietary profile than non-coffee consumers, including greatly reduced contribution of fruits, vegetables and legumes to total phenolic intake. Coffee drinkers were more likely to be non-vegetarians, which explained several of these observations. Further evaluating these differences may be important in identifying relationships between plant-based diets and health outcomes.

The aim of the present study was to analyse the effects of partial or total replacement of fish meal (FM) and fish oil (FO) by a mixture of plant protein (PP) and a mixture of vegetable oils (VO) on the hepatic insulin–nutrient-signalling pathway and intermediary metabolism-related gene expression in rainbow trout (Oncorhynchus mykiss). Triplicate groups of fish were fed four practical diets containing graded levels of replacement of FM and FO by PP and VO for 12 weeks: diet 0/0 (100 % FM, 100 % FO); diet 50/50 (50 % FM and 50 % PP, 50 % FO and 50 % VO); diet 50/100 (50 % FM and 50 % PP, 100 % VO); diet 100/100 (100 % PP, 100 % VO). Samplings were performed on trout starved for 5 d then refed with their allocated diet. In contrast to partial substitution (diet 50/50), total substitution of FM and FO (diet 100/100) led to significantly lower growth compared with diet 0/0. The insulin–nutrient-signalling pathway (protein kinase B (Akt), target of rapamycin (TOR), S6 protein kinase 1 (S6K1) and S6) was characterised in trout liver and found to be activated by refeeding. However, changes in diet compositions did not differentially affect the Akt–TOR-signalling pathway. Moreover, expression of genes encoding fructose-1,6-biphosphatase, mitochondrial phosphoenolpyruvate carboxykinase, glucokinase, pyruvate kinase and carnitine palmitoyl transferase 1 were not affected by refeeding or by dietary changes. Refeeding down- and up-regulated the expression of gluconeogenic glucose-6-phosphatase isoform 1 and lipogenic fatty acid synthase genes, respectively. Expression of both genes was also increased with partial replacement of FM and total replacement of FO (diet 50/100). These findings indicate that plant-based diets barely affect glucose and lipid metabolism in trout.

The adequacy of plant-based diets in developed and developing countries as sources of protein and amino acids for human subjects of all ages is examined. Protein quantity is shown not to be an issue. Digestibility is identified as a problem for some cereals (millet (Panicum miliaceum) and sorghum (Sorghum sp.)) and generally is poorly understood. Direct measurements of biological value in children are reviewed and scoring is consid-ered. Various existing requirement values for amino acids and especially lysine are reviewed, and it is concluded that stable-isotope studies do not yet provide adequate alternative values to N balance data, which for lysine are robust after recalculation and adjustment. A new maintenance requirement pattern is developed, with higher values than those of Food and Agriculture Organization/World Health Organization/United Nations University (1985) but lower values than the Massachusetts Institute of Technol-ogy pattern (Young et al. 1989). Calculations of age-related amino acid requirements are based on most recent estimates of human growth and maintenance protein requirements, a tissue amino acid pattern and the new maintenance amino acid pattern. These values appear valid when used to score plant proteins, since they indicate values similar to or less than the biological value measured directly in young children. When used to score plant-based diets in India, no marked deficiencies are identified. All regions score > 1 for adults, whilst for children scores range from > 1, (Tamil Nadhu) from 6 months of age to 0.78 (West Bengal), rising to 0.9 in the 2–5 year old, consistent with reports that high-lysine maize supports similar weight and height growth to that of casein. Inadequate amino acid supply is not an issue with most cereal-based diets.

An ideal diet is one that promotes optimal health and longevity. Throughout history, human societies have developed varieties of dietary patterns based on available food plants and animals that successfully supported growth and reproduction. As economies changed from scarcity to abundance, principal diet-related diseases have shifted from nutrient deficiencies to chronic diseases related to dietary excesses. This shift has led to increasing scientific consensus that eating more plant foods but fewer animal foods would best promote health. This consensus is based on research relating dietary factors to chronic disease risks, and to observations of exceptionally low chronic disease rates among people consuming vegetarian, Mediterranean and Asian diets. One challenge to this consensus is the idea that palaeolithic man consumed more meat than currently recommended, and that this pattern is genetically determined. If such exists, a genetic basis for ideal proportions of plant or animal foods is difficult to determine; hominoid primates are largely vegetarian, current hunter—gatherer groups rely on foods that can be obtained most conveniently, and the archeological record is insufficient to determine whether plants or animals predominated. Most evidence suggests that a shift to largely plant-based diets would reduce chronic disease risks among industrialized and rapidly industrializing populations. To accomplish this shift, it will be necessary to overcome market-place barriers and to develop new policies that will encourage greater consump-tion of fruits, vegetables and grains as a means to promote public health.