Greenhouse gas emissions of realistic dietary choices in Denmark: the carbon footprint and nutritional value of dairy products

A qualitative study of young peoples' thoughts and attitudes to follow a more plant-based diet

Plant-based diets (PBDs) refer to dietary habits that reduce the consumption of animal-based products and increase the consumption of nutritionally rich plant foods. PBD's have been shown to provide significant health benefits, such as reducing obesity and improving psychological wellbeing, and are environmentally friendly. However, few studies have investigated factors that influence young people's thoughts and attitudes toward following a PBD in western societies, particularly in the United Kingdom. Understanding these factors may benefit public health interventions that encourage the consumption of more fruit and vegetables. The aim of this study was to explore the factors that affect young people's intentions toward following a PBD. Twenty-one young people (18-24 years) participated in this qualitative study. Participants were asked about their views of PBDs in a semi-structured interview. Thematic analysis was utilized to explore views and the barriers and facilitators to following a PBD. The Theory of Planned Behavior (TPB) was used as a framework to organise the findings. Within attitudes, the sub-themes identified were an awareness of a healthy diet, environmental concerns, health concerns and distrust, perceptions of PBDs and associated stereotypes, perceived restriction and lack of enjoyment, and need for education. Within subjective norms, the sub-themes identified were cultural and familial norms, peer influence, and exposure through social media. Within perceived behavioral control (PBC), the sub-themes identified were a lack of independence and parental control, lack of knowledge and perceived difficulty, lack of inclusiveness and accessibility, and inconvenience. Overall, the findings suggest that increased provision of education and knowledge about PBDs to young people, and widening access to PBDs, could encourage and help improve their understanding and intention to follow this dietary style. Tailored health promotion strategies, which also consider additional barriers and facilitators found within this study, could motivate young people to consume a more PBD.

The Environmental Sustainability of Plant-Based Dietary Patterns: A Scoping Review

BACKGROUND

A large part of the existential threat associated with climate change is the result of current human feeding patterns. Over the last decade, research evaluating the diet-related environmental impacts of plant-based diets has emerged, and a synthesis of the available data is now due.

OBJECTIVES

The objectives of the study were as follows: 1) to compile and summarize the literature on diet-related environmental impacts of plant-based dietary patterns; 2) to assess the nature of the data on impacts of plant-based dietary patterns on both environmental parameters and health (e.g., if land use is reduced for a particular diet, is cancer risk also reduced?); and 3) to determine where sufficient data exist for meta-analyses, in addition to identifying gaps within the literature.

METHODS

Global peer-reviewed studies on the environmental impacts of plant-based diets were searched in Ovid MEDLINE, EMBASE, and Web of Science. After removing duplicates, the screening identified 1553 records. After 2 stages of independent review by 2 reviewers, 65 records met the inclusion criteria and were eligible to be used in synthesis.

RESULTS

Evidence suggests that plant-based diets may offer lower greenhouse gas emissions (GHGEs), land use, and biodiversity loss than offered by standard diets; however, the impact on water and energy use may depend on the types of plant-based foods consumed. Further, the studies were consistent in demonstrating that plant-based dietary patterns that reduce diet-related mortality also promote environmental sustainability.

CONCLUSIONS

Overall, there was agreement across the studies regarding the impact of plant-based dietary patterns on GHGE, land used, and biodiversity loss despite varied plant-based diets assessed.

Dietary modeling of greenhouse gases using OECD meat consumption/retail availability estimates

Research has demonstrated different carbon footprints, based on portion estimations. However, previous estimates are low and often omit the impact of food waste. For example, a high-level of daily meat consumption has been estimated at 100 g, which is less than a typical “quarter pounder” hamburger. We used the Organization for Economic Co-operation and Development (OECD) annual estimates of national retail availability, and applied a mathematical model to prorate other research results to determine a meat portion equal to current OECD statistics, and also projected the diets to 2500 and 3250 kcal, to include consumer and retail waste. Once prorated, the 14 national studies are contrasted and analyzed for reasonableness against OECD data pertaining to U.S., U.K., E.U., vegetarian and vegan diets. We quantify how previous studies underestimated greenhouse gas (GHG) emissions and show that previous GHG study results for the highest tier most accurately predict average national dietary consumption.

Environmental impacts and diet quality of popular diet models compared to Turkey's national nutrition guidelines

AIMS

This study aimed to compare the environmental impacts and diet qualities of popular diet models with the recommendations of the Turkish national dietary guidelines.

METHODS

Seven-day isocaloric (8368 kJ) diet models were created taking into account the Mediterranean, Atkins (20/40/100), Ornish, Zone diets, and Turkey Dietary Guidelines-2015 recommendations with different food and nutrient contents. Water footprints were evaluated using the global water footprint standards. Greenhouse gas emissions were evaluated using carbon footprint factors compiled as a result of meta-analyses of life cycle analysis studies in the literature. In addition, the quality of diets was evaluated with the Diet Quality Index-International.

RESULTS

Atkins20 diet model had the most harmful environmental impact (greenhouse gas emissions 8.74 kg CO₂ -eq/per/day and total water footprint 7731 L/per/day), whereas Ornish and Mediterranean diet models (greenhouse gas emissions 2.2/3.07 kg CO₂ -eq/per/day and total water footprints 3184/3675 L/per/day, respectively) had less harmful environmental impact. The highest Diet Quality Index-International score was in the Ornish diet model while the lowest Diet Quality Index-International was in the Atkins20 diet model.

CONCLUSION

Ornish and Mediterranean diet models had less harmful environmental impacts, which contributed to sustainable nutrition. The importance of diet quality and environmental impacts should be kept in mind when evaluating diet models to ensure sustainable nutrition.

Dairy Trade Helps to Alleviate Global Carbon Emission Pressure

Global dairy production, consumption, and trade are growing rapidly, driven by population and per capita income growth and increasing health concerns mainly from developing countries, which has aroused concerns about the related carbon emission (mostly in the form of methane) increase. If all of the dairy products consumed were produced locally/domestically in the developing countries/economies (a counterfactual scenario), the carbon emissions in 2018 would be 28 Mt CO₂-equiv higher than its status quo (a factual scenario). The present study indicates that unlike in many global trade cases in which carbon leakages are from developed to developing countries, global dairy trade is characterized by net embodied carbon flows from developed to developing countries/economies due to the fact that there is an overwhelming one-way-flow of dairy products from developed to developing countries/economies. The differences in the carbon emission factors between the developed and developing countries/economies provide an opportunity that global dairy trade and production specialization can help to reduce carbon emissions from increasing dairy product demand, and the total reduction potential is estimated to be about 414 Mt CO₂-equiv from 2018 to 2030. Free trade agreements such as the Regional Comprehensive Economic Partnership will incentivize larger carbon emission reduction benefits through promoting dairy trade.

The Chilean Diet: Is It Sustainable?

Food systems are one of the main contributors to climate change. Sustainable diets are one strategy to mitigate climate change. Assessments and estimations at a national level are lacking, especially in the Global South, probably due to a lack of national surveys of food consumption and a limited interest in sustainable diets information. The objective of this study is to estimate and describe the carbon and water footprint of the Chilean population’s diet in an overall estimation desegregated by region, age, sex, socioeconomic level and their main characterizations. This study is based on a secondary data analysis from the National Survey of Food Consumption made in 2010. The carbon and water footprint of the food subgroups/person/day were estimated. The results are compared by sex, age group, socioeconomic level, and macro zone. A carbon footprint of 4.67 kg CO_2eq and a water footprint of 4177 L, both per person/day, were obtained. Animal-sourced foods, such as dairy and red meat, were responsible for 60.5% of the total carbon footprint and 52.6% of the water footprint. The highest values for both footprints were found in the following groups: men, adolescents, young adults, people with a higher socioeconomic level, and residents in the southern area of the country. The carbon footprint and water footprint values in Chile generated by food consumption would be above the world averages. Transforming the Chilean food system into a more sustainable one with changes in eating patterns is urgently required to attain this transformation.

Greenhouse gas emissions in the food system: Current and alternative dietary scenarios

BACKGROUND: There is a growing interest in diets due to the high contribution to greenhouse gas emissions (GHGE). OBJECTIVE: The study was aimed to estimate the impact on GHGE of replacing the current diet with eight alternative diets, which would be associated with GHGE, to contribute to the discussion of how dietary changes affect the GHGE. METHODS: The latest National Nutrition and Health Survey was utilized to determine the nutrient composition of Turkey’s current diet, with eight dietary scenarios designed to meet the National Dietary Guidelines. RESULTS: The current diet had the highest GHGE with 3254.50 g CO2eq/person/day with beef, lamb, and cheese products accounting for the majority of emissions (18.61%, 17.15%, and 10.89%, respectively). The Model diet had a GHGE of 2994.18 g CO2eq/person/day, whereas vegetarian diets had the lowest (lacto-ovo vegetarian diet with 1944.95 g CO2eq/person/day and vegan diet with 1166.80 g CO2eq/person/day). Low energy efficiencies were associated with high diet-related GHGE levels. CONCLUSION: When evaluating future dietary guidelines for a sustainable diet, our study highlighted the need of integrating both health and environmental aspects. The present study found that dietary changes would significantly contribute to lowering GHGE. These findings will be beneficial in informing Turkey’s nutrition, agriculture, and public policymakers.

Animal board invited review: Animal source foods in healthy, sustainable, and ethical diets - An argument against drastic limitation of livestock in the food system

Animal source foods are evolutionarily appropriate foods for humans. It is therefore remarkable that they are now presented by some as unhealthy, unsustainable, and unethical, particularly in the urban West. The benefits of consuming them are nonetheless substantial, as they offer a wide spectrum of nutrients that are needed for cell and tissue development, function, and survival. They play a role in proper physical and cognitive development of infants, children, and adolescents, and help promote maintenance of physical function with ageing. While high-red meat consumption in the West is associated with several forms of chronic disease, these associations remain uncertain in other cultural contexts or when consumption is part of wholesome diets. Besides health concerns, there is also widespread anxiety about the environmental impacts of animal source foods. Although several production methods are detrimental (intensive cropping for feed, overgrazing, deforestation, water pollution, etc.) and require substantial mitigation, damaging impacts are not intrinsic to animal husbandry. When well-managed, livestock farming contributes to ecosystem management and soil health, while delivering high-quality foodstuffs through the upcycling of resources that are otherwise non-suitable for food production, making use of marginal land and inedible materials (forage, by-products, etc.), integrating livestock and crop farming where possible has the potential to benefit plant food production through enhanced nutrient recycling, while minimising external input needs such as fertilisers and pesticides. Moreover, the impacts on land use, water wastage, and greenhouse gas emissions are highly contextual, and their estimation is often erroneous due to a reductionist use of metrics. Similarly, whether animal husbandry is ethical or not depends on practical specificities, not on the fact that animals are involved. Such discussions also need to factor in that animal husbandry plays an important role in culture, societal well-being, food security, and the provision of livelihoods. We seize this opportunity to argue for less preconceived assumptions about alleged effects of animal source foods on the health of the planet and the humans and animals involved, for less top-down planning based on isolated metrics or (Western) technocratic perspectives, and for more holistic and circumstantial approaches to the food system.

Exploring the pathways towards the mitigation of the environmental impacts of food consumption

Agriculture constitutes a quarter and more than a third of Denmark's global greenhouses gas (GHG) emissions and natural resource consumption, respectively. This paper aims to estimate the potential to lower Denmark's global food-related GHG, blue water and land footprints using the most recent version of a hybrid global multi-regional input-output (MRIO) database, EXIOBASE of the reference year, 2011. Specifically, we apply the 'what if' scenario-based MRIO approach to EXIOBASE and quantify the impact of increased livestock feed efficiency (FE), dietary changes, food loss and waste (FLW) reduction/prevention and food waste treatment scenarios on Denmark's global food-related GHG and resource footprints. We obtain modest reductions in Denmark's global food-related GHG, blue water and cropland footprint from the combination of livestock FE improvements and FLW reduction; 61 kt CO₂e, 2 Mm³ and 30 kha, respectively. In contrast, dietary change towards no/less meat and dairy diets embodies the most significant reductions potential for Denmark's total global food-related GHG, blue water, croplands and grassland footprint by up to 34% (3.63 Mt. CO₂e), 8% (90 Mm³), 23% (371 kha) and 78% (386 kha) respectively. A key policy priority should therefore be the nudging of Danish consumers towards sustainable diets. Also, this study's findings emphasise that FLW prevention remains the most effective food waste-related climate mitigation and resource efficiency strategy despite the benefits of food waste valorisation.

The role of livestock in sustainable food production systems in Canada

Global drivers such as the growing human population, evolving consumer preferences, globalization, and climate change have put pressure on the agri-food sector to produce more livestock products with less land, feed, and water. Taste, nutritional value, cost, convenience, source, animal welfare, and environmental sustainability of food are criteria upon which purchasing decisions are made. In response, an environmental footprint analysis composed of greenhouse gas emissions, nutrient and water use efficiency, water quality, carbon storage, and biodiversity has been completed for many commodities. However, as livestock production systems occur within complex agro-ecosystems, it is extremely challenging to formulate a single overall sustainability metric. There is no “silver bullet” to solve the environmental concerns of all livestock production systems as they operate under different constraints on different landscapes, with different water and nutrient cycles, and soil types. Furthermore, the lack of scientific evidence regarding the interactions between livestock production, human nutritional adequacy, and the health of our environment makes it difficult for consumers to interpret this information and make informed food choices. This review examines these complex interactions and trade-offs, as well as the potential impacts of changes in consumer dietary choice on environmental sustainability, nutritional adequacy, and land use.

Differences in Environmental Impact between Plant-Based Alternatives to Dairy and Dairy Products: A Systematic Literature Review

A large body of research suggests a more plant-based diet, including a switch to plant-based alternatives to dairy, is needed for lowering human-induced climate change as well as land and water use. With the help of a systematic literature review, we analyzed data from 21 peer-reviewed articles about the differences in emissions and resources used between various plant-based alternatives to dairy and dairy products. Emissions included were greenhouse gases, acidifying, eutrophicating, and ozone-depleting substances, and resource use included water, energy, and land. The results are presented as the quotients of the ratios of plant-based alternatives to dairy and dairy products. The comparison shows that the plant-based dairy alternatives have lower, or much lower, impacts in almost all cases, with two exceptions: water use for almond drinks (several studies) and emissions of ozone-depleting substances for margarine (one study). There is a lack of data concerning impacts other than greenhouse gas emissions for plant-based cheese alternatives; and in general, emissions of greenhouse gases are more highly covered than other impacts. In the quest for a swift transition to a low carbon economy, however, there is already enough evidence to proceed with a dietary change involving switching dairy products to plant-based alternatives.

Consumer Choice for Milk and Dairy in Romania: Does Income Really Have an Influence?

Milk and dairy are basic food products and their importance in healthy human development is well known. However, this does not mean that the consumers’ requests for these products are not evolving and fitting into the new context of sustainable development. By conducting a quantitative analysis on 847 answers regarding milk and dairy consumption offered by Romanian consumers, the objective of this study is to reveal what are the main factors of influence for respondents when choosing a milk or dairy product, and to see if these factors are evolving towards including sustainability-related aspects. The results point out that while price and store availability are still present as choice criteria, new aspects that might be related to a sustainable behavior, such as ecologic certification, country of origin or traditional products, are considered by the respondents when purchasing milk and dairy. However, this depends on the level of income; higher incomes allow respondents to consider new criteria.

Nutritional quality and carbon footprint of university students' diets: results from the EHU12/24 study

Objective:

To evaluate diets in terms of nutritional characteristics and quality from the perspectives of health, greenhouse gas emissions (GHGE) and possible associations with each other in a representative sample of students at a public university.

Design:

Cross-sectional. Dietary intake was evaluated with a validated FFQ, and diet quality was assessed through the Healthy Eating Index (HEI-2010) and MedDietScore (MDS). GHGE data were obtained from the literature. In addition, sex, socio-economic status (SES) and body fat (BF) status were analysed as covariates.

Setting:

Basque Autonomous Community, Spain.

Participants:

Totally, 26 165 healthy adults aged 18–28 years.

Results:

Student diets were characterised by low consumption of carbohydrates (38·72 % of total energy intake (TEI)) and a high intake of lipids (39·08 % of TEI). Over half of the participants had low dietary quality. The low-emitting diets were more likely to be consumed by subjects with low HEI-2010 scores (β: 0·039 kg eCO₂/1000 kcal/d) and high MDS scores (β: −0·023 kg eCO₂/1000 kcal/d), after controlling for sex, SES and BF status. Both the low-emitting and healthy diets were more likely to be consumed by women and by those with normal BF percentage.

Conclusions:

UPV/EHU university students’ diets were characterised by moderate quality from a nutritional perspective and moderate variation in the size of carbon footprints. In this population, diets of the highest quality were not always those with the lowest diet-related GHGE; this relationship depended in part on the constructs and scoring criteria of diet quality indices used.

Sustainable Agri-Food Systems: Environment, Economy, Society, and Policy

Agri-food systems (AFS) have been central in the debate on sustainable development. Despite this growing interest in AFS, comprehensive analyses of the scholarly literature are hard to find. Therefore, the present systematic review delineated the contours of this growing research strand and analyzed how it relates to sustainability. A search performed on the Web of Science in January 2020 yielded 1389 documents, and 1289 were selected and underwent bibliometric and topical analyses. The topical analysis was informed by the SAFA (Sustainability Assessment of Food and Agriculture systems) approach of FAO and structured along four dimensions viz. environment, economy, society and culture, and policy and governance. The review shows an increasing interest in AFS with an exponential increase in publications number. However, the study field is north-biased and dominated by researchers and organizations from developed countries. Moreover, the analysis suggests that while environmental aspects are sufficiently addressed, social, economic, and political ones are generally overlooked. The paper ends by providing directions for future research and listing some topics to be integrated into a comprehensive, multidisciplinary agenda addressing the multifaceted (un)sustainability of AFS. It makes the case for adopting a holistic, 4-P (planet, people, profit, policy) approach in agri-food system studies.

Diet-related greenhouse gas emissions and major food contributors among Japanese adults: comparison of different calculation methods

OBJECTIVE

To develop a greenhouse gas emissions (GHGE) database for Japanese foods using three different approaches, compare the results of estimated diet-related GHGE and determine major food contributors among Japanese adults.

DESIGN

Cross-sectional. Three GHGE databases were developed: (1) a literature-based method including a literature review of life cycle assessment studies of Japanese foods and (2) production- and (3) consumption-based input-output tables (IOT)-applied methods using the Japanese IOT. All databases were linked to the Japanese food composition table and food consumption data. Diet-related GHGE was estimated based on each database and the 4-d dietary record data. Diet-related GHGE were compared in both total and food group level between the databases.

SETTING

Japan.

PARTICIPANTS

392 healthy adults aged 20-69 years.

RESULTS

The mean diet-related GHGE significantly differed according to the calculation methods: 4145 g CO2-equivalent (CO2-eq)/d by the literature-based method, 4031 g CO2-eq/d by the production-based method and 7392 g CO2-eq/d by the consumption-based IOT-applied methods. It significantly differed in food group level as well. Spearman's correlation coefficients between three methods ranged from 0·82 to 0·86. Irrespective of the methods, the top contributor to GHGE was meat (19·7-28·8 %) followed by fish and seafood (13·8-18·3 %).

CONCLUSIONS

Although the identified major food contributors to GHGE were comparable between the three methods, the estimated GHGE values significantly differed by calculation methods. This finding suggested that caution must be taken when interpreting the estimated diet-related GHGE values obtained using the different calculation methods of GHGE.

An Application of the Theory of Planned Behaviour to Predict Intention to Consume Plant-Based Yogurt Alternatives

This study attempts to predict plant-based yogurt consumers’ intention to consume plant-based yogurt alternatives in Denmark employing Ajzen’s theory of planned behaviour as a theoretical framework. An online survey was conducted among 265 consumers recruited through convenience (snowball) sampling. The results from structural equation modelling analysis show that attitude (β = 0.216, p < 0.001), perceived behavioural control (self-efficacy) (β = 0.229, p < 0.001) and perceived sensory attributes (β = 0.324, p < 0.001) positively and significantly influenced consumers’ intention to consume plant-based yogurt alternatives. However, subjective norms (β = 0.106, p = 0.087) and perceived barriers (β = −0.051, p = 0.414) did not influence consumers’ intention to consume plant-based yogurt alternatives. Further, objective knowledge showed no significant influence on attitudes (β = 0.077, p = 0.242) and intention (β = −0.029, p = 0.603) towards plant-based yogurt alternatives. The intention (β = 0.677, p < 0.001) to consume plant-based yogurt alternatives showed a strong positive correlation with the behaviour to consume plant-based yogurt alternatives. The results from logistic regression indicated that socio-demographic characteristics, gender, education, income and region of residence were significantly associated with consumption of plant-based yogurt alternatives. Thus, focusing on consumers’ attitudes and self-efficacy and improving the organoleptic characteristics might promote the consumption of plant-based yogurt alternatives in Denmark and similar countries.

The Climate and Nutritional Impact of Beef in Different Dietary Patterns in Denmark

There is public focus on the environmental impact, and in particular, the emissions of greenhouse gases (GHG), related to our food consumption. The aim of the present study was to estimate the carbon footprint (CF), land use and nutritional impact of the different beef products ready to eat in different real-life dietary patterns. Beef products accounted for 513, 560, 409 and 1023 g CO₂eq per day, respectively, in the four dietary patterns (Traditional, Fast-food, Green, and High-beef). The total CFs of these diets were 4.4, 4.2, 4.3 and 5.0 kg CO₂eq per day (10 MJ)_, respectively. The Green diet had almost the same CF as the Traditional and the Fast-food diets despite having the lowest intake of beef as well as the lowest intake of red meat in total. A theoretical substitution of beef with other animal products or legumes in each of these three diets reduced the diets' CF by 4-12% and land use by 5-14%. As regards nutrients, both positive and negative impacts of these substitutions were found but only a few of particular nutritional importance, indicating that replacing beef with a combination of other foods without a significant effect on the nutrient profile of the diet is a potential mitigation option.

Evaluation of environmental performance of dietary patterns in the United States considering food nutrition and satiety

Food production substantially depletes the environment in different ways, but little is known about how overall dietary patterns relate to these environmental impacts. The objective of this study was to evaluate the environmental performance of different dietary patterns among U.S. adults using life cycle assessment (LCA). A "typical" dietary pattern was compared with those recommended by the Dietary Guidelines for Americans, including "healthy U.S.", Mediterranean and lacto-ovo vegetarian. Supplemental functional units (FUs) were applied to incorporate the functions of food to provide nutrition and satiety, namely Nutrient Rich Foods Index 9.3 (NRF9.3), Nutritional Quality Index (NQI), and Fullness Factor™ (FF). Life cycle inventory data was collected for 14 food categories consisting of 76 component foods, and their midpoint environmental impacts were calculated, with particular focus on global warming potential. Diets in accordance with different patterns were constructed from selected component foods at a reference energy amount of 2000 kcal. Vegetarian diets on average generated the lowest carbon footprint regardless of the FU. However, large possible variations in the environmental profiles of the compared diets were identified due to the wide range of food choices within a pattern, which showed highly different nutrition and satiety scores even within the same food category. Animal products, including meat and dairy especially, and discretionary foods were identified as the specific food categories that contributed the most to the global warming potential. Discretionary foods consistently exhibited higher impacts on the basis of nutritional FUs due to their low nutrient density. The results can be implied as practical guidelines to help reduce the carbon footprint associated with current U.S. diets without compromising their nutritional adequacy and satiety.

The role of dairy foods in lower greenhouse gas emission and higher diet quality dietary patterns

PURPOSE

There is conflicting advice about the inclusion of dairy foods in a lower greenhouse gas (GHG) emission dietary pattern. Our purpose was to assess the prevalence of dairy food intake among higher diet quality and lower GHG emission diets in Australia and within these diets assess the association between level of dairy food intake and adequate intake of a broad range of nutrients.

METHODS

Dietary intake data collected using a 24-h recall process were sourced from the most recent Australian Health Survey. Diet quality was assessed by level of compliance with the food group-based Australian Dietary Guidelines. A subgroup of 1732 adult (19 years and above) daily diets was identified having higher diet quality score and lower GHG emissions (HQLE). Intake of core dairy foods (milk, cheese, yoghurt) was assessed and nutrient profiling was undertaken for 42 macro- and micronutrients.

RESULTS

The HQLE subgroup had 37% higher diet quality score and 43% lower GHG emissions than the average Australian adult diet (P < 0.05). Intake of dairy foods was very common (90% of HQLE diets) and greatly exceeded the intake of non-dairy alternatives (1.53 serves compared to 0.04 serves). HQLE daily diets in the highest tertile of dairy food intake were more likely to achieve the recommended intake of a wide range of nutrients, including calcium, protein, riboflavin, vitamin B12, folate, phosphorous, magnesium, iodine and potassium compared to other HQLE daily diets.

CONCLUSION

Core dairy foods have an important role for achieving adequate nutrient intakes in a healthy and lower GHG emission dietary pattern in Australia.

Vegetarian Diets: Planetary Health and Its Alignment with Human Health

To maintain planetary health, human activities must limit the use of Earth's resources within finite boundaries and avoid environmental degradation. At present, food systems account for a substantial use of natural resources and contribute considerably to climate change, degradation of land, water use, and other impacts, which in turn threaten human health through food insecurity. Additionally, current dietary patterns, rich in animal products and excessive in calories, are detrimental to both population and planetary health. In order to resolve the diet-environment-health trilemma, population-level dietary changes are essential. Vegetarian diets are reported to be healthy options. Most plant-sourced foods are less resource intense and taxing on the environment than the production of animal-derived foods, particularly meat and dairy from ruminants. This review article explores simultaneously the environmental sustainability of vegetarian diets, and its alignment with people's health. In general, the progression from omnivorous to ovolactovegetarian and vegan diets is associated with increased environmental sustainability. Greenhouse gas emissions resulting from vegan and ovolactovegetarian diets are ∼50% and ∼35% lower, respectively, than most current omnivore diets, and with corresponding reductions in the use of natural resources. Concomitant health benefits could be obtained by shifting from current dietary patterns to sustainable vegetarian diets. Thus, there seems to be an alignment of health and environmental outcomes for vegetarian diets. Although this shows the human health and environmental sustainability benefits of vegetarian diets in high-income countries, questions remain about the challenges in other contexts and the political will to promote meat-free diets as the social norm.

Linking environmental sustainability and nutritional quality of the Atlantic diet recommendations and real consumption habits in Galicia (NW Spain)

Today's society is increasingly aware of food consumption patterns. Under the perspective that real consumption trends are often not in line with healthy recommendations, this research focuses on the study of the environmental and nutritional sustainability of two types of food consumption habits present in the northern Atlantic area of Spain (Galicia). The main objective is, therefore to detect the existing deviations between the current Galician diet (GD) and the traditional and increasingly relevant Recommended Atlantic Diet (RAD), allowing verifying whether current consumption patterns ensure an optimal and sustainable nutritional profile. In this sense, the carbon footprint from a Life Cycle Assessment perspective has been estimated as environmental indicator of both dietary patterns and, the nutritional quality has been determined by the Nutrient Rich Diet 9.3 index and the Health gain score. The carbon footprint of both dietary models is moderately high compared to recommended diets such as the Mediterranean one. Comparing the two scenarios, the associated greenhouse gas emissions are about 15% higher for GD than for RAD, mainly due to the higher intake of beef and dairy products. On the other hand, nutritional quality is comparatively higher for RAD than for GD, associated with higher consumption of vegetables and fruits. An additional objective of this work has been to consider a sensitivity analysis to determine the effect of replacing beef with alternative sources. Having in mind this study, it can be concluded that the real consumption pattern in Galicia is far from the recommended one, with worse environmental and nutritional quality. The promotion of social awareness policies to guide consumers in the choice a healthier and more environmentally sustainable dietary pattern should be advisable for regional decision-makers as well as for those who wish to promote adherence to the Atlantic diet in other regions and countries.

Exploring the Relationship between Environmental Impact and Nutrient Content of Sandwiches and Beverages Available in Cafés in a UK University

The threat of climate change and population growth has led to calls for the adoption of environmentally sustainable diets; however, concerns have been raised over the nutritional quality of low Greenhouse Gas Emission (GHGE) diets. This study examined the relationship between measures of environmental sustainability and nutrient content of sandwiches and beverages sold in a UK university café. GHGE and Water Footprint Impact Indicator (WFII) values for the ingredients of sandwiches and beverages were used with recipe information to calculate GHGE (gCO2e per portion) and WFIIs (scarcity weighted litres per portion). These estimates were then combined via orthogonal regression to produce a single Environmental Impact Score (EIS); higher scores equate to greater environmental impact. The relationship between EIS and nutrient content was explored using correlation analysis. Sandwiches that contained meat and animal products as well as beverages that contained milk, cocoa, and/or coffee had the highest EIS. EIS was positively associated with the portion size of sandwiches but not the serving size of beverages. EIS was positively correlated with calories, saturated fat, and sodium. However, EIS was also positively correlated with micronutrients: iron, calcium (beverages only), and B12 (beverages only). The choice of smaller or plant-based sandwiches as well as beverages without milk would reduce environmental impact as well as caloric and sodium intake. However, the selection of low impact options may also reduce the intake of nutrients required for good health. This study revealed possible tensions between nutritional quality and environmental sustainability.

Carbon footprint and nutritional quality of different human dietary choices

Apart from industrial activities, our eating habits also have a significant environmental cost associated with crop cultivation, manufacturing processes, packaging, refrigeration, transport cooking and waste management. In a context of growing social awareness of the role of different dietary choices in the environment, the review of different alternatives on the road to a healthy and sustainable diet should integrate relevant information on the nutritional quality of different eating habits. Since dietary choices have an effect on environmental sustainability and human health, a literature review on different dietary choices has been conducted to determine the differences in carbon footprint and nutritional quality identifying the main hotspots trying to give advice towards the identification of sustainable diets. After applying a set of criteria for reference selection, 21 peer-reviewed studies have been analysed in detail, allowing the comparison of 66 dietary scenarios. We identified that the so-called Mediterranean and Atlantic diets present high nutritional scores and low carbon footprints. On the contrary, the dietary choices identified in northern and Western Europe, as well as in the United States, have the highest carbon footprints, highlighting the contribution of dairy products as a basic source of high-quality nutrients and protein. Broadly speaking, dietary choices rich in vegetables (e.g., vegan, vegetarian as well as Indian and Peruvian) have a better environmental profile than those rich in meat (mainly ruminant meat). In line with these findings, the shift in meat consumption habits from beef and veal to chicken, pork and poultry, the introduction of alternative foods to animal protein (e.g. quinoa) and the consumption of olive oil as a major source of vegetable oil may be compatible with a healthier and more environmentally friendly diet. However, the complete elimination of meat and dairy products from the daily diet may not be feasible in case the supply of some micronutrients (e.g., calcium and vitamin D) is not guaranteed. Limitations were identified in the consulted studies related to the consideration of the different system boundaries, as well as underlying uncertainties related to data sources. Therefore, efforts should be made to develop consistent and agreed-upon methods for estimating both the carbon footprint and nutritional quality scores.

Comparing the Performance of Bread and Breakfast Cereals, Dairy, and Meat in Nutritionally Balanced and Sustainable Diets

Objective: To quantify the performance of food products in a sustainable diet based on the balance of their contribution to nutrient intake and environmental impact, within the context of the Dutch diet. Design: While fixing the quantity of a specific food group at different levels, optimized diets that met nutrient requirements and stayed as close as possible to the current Dutch diet were calculated, in order to understand its potential environmental impact and its nutritional quality. Bread & breakfast cereals, dairy, and meat were compared between 0 and 250% of current intake. Their performance is expressed in the relationship between the quantity of these food products and (1) the environmental impact of diets and (2) the nutrient balance of the diets. Setting: The Netherlands. Subjects: Women aged 31-50. Results: The amount of bread & breakfast cereals in the optimized diets were inversely correlated with their environmental impact. The nutrient balance of the optimized diets was maintained despite varying cereal content, with the expected improvement over the current diet. Increasing amounts of dairy in the optimized diet were associated with an increase in environmental impact and meat with a steep increase. The nutrient balance of optimized diets with varying dairy and meat contents was also maintained at high levels, even at 0% content. Conclusions: Bread and breakfast cereals are sources of nutrients with a better environmental performance compared to dairy or meat within the context of the Dutch diet. It is possible to optimize diets for environmental impact whilst maintaining a high nutrient balance.

Climate change mitigation opportunities based on carbon footprint estimates of dietary patterns in Peru

Food consumption accounts for an important proportion of the world GHG emissions per capita. Previous studies have delved into the nature of dietary patterns, showing that GHG reductions can be achieved in diets if certain foods are consumed rather than other, more GHG intensive products. For instance, vegetarian and low-meat diets have proved to be less carbon intensive than diets that are based on ruminant meat. These environmental patterns, increasingly analyzed in developed nations, are yet to be assessed in countries liked Peru where food purchase represents a relatively high percentage of the average household expenditure, ranging from 38% to 51% of the same. Therefore, food consumption can be identified as a potential way to reduce GHG emissions in Peru. However, the Peruvian government lacks a specific strategy to mitigate emissions in this sector, despite the recent ratification of the Paris Accord. In view of this, the main objective of this study is to analyze the environmental impacts of a set of 47 Peruvian food diet profiles, including geographical and socioeconomic scenarios. In order to do this, Life Cycle Assessment was used as the methodological framework to obtain the overall impacts of the components in the dietary patterns observed and primary data linked to the composition of diets were collected from the Peruvian National Institute for Statistics (INEI). Life cycle inventories for the different products that are part of the Peruvian diet were obtained from a set of previous scientific articles and reports regarding food production. Results were computed using the IPCC 2013 assessment method to estimate GHG emissions. Despite variations in GHG emissions from a geographical perspective, no significant differences were observed between cities located in the three Peruvian natural regions (i.e., coast, Andes and Amazon basin). In contrast, there appears to be a strong, positive correlation between GHG emissions and social expenditure or academic status. When compared to GHG emissions computed in the literature for developed nations, where the average caloric intake is substantially higher, diet-related emissions in Peru were in the low range. Our results could be used as a baseline for policy support to align nutritional and health policies in Peru with the need to reduce the environmental impacts linked to food production.

Dietary Strategies to Reduce Environmental Impact: A Critical Review of the Evidence Base

The food system is a major source of environmental impact, and dietary change has been recommended as an important and necessary strategy to reduce this impact. However, assessing the environmental performance of diets is complex due to the many types of foods eaten and the diversity of agricultural production systems and local environmental settings. To assess the state of science and identify knowledge gaps, an integrative review of the broad topic of environment and diet was undertaken, with particular focus on the completeness of coverage of environmental concerns and the metrics used. Compared with the 14 discrete environmental areas of concern identified in the United Nations Sustainable Development Goals, the located journal literature mainly addressed greenhouse gas (GHG) emissions and, to a lesser extent, land and water use. Some relevant concerns were rarely addressed or not addressed at all. In the case of GHG emissions, changes in land use and soil carbon stocks were seldom considered. This represents a disconnect between the science informing strategic climate action in the agricultural sector and the science informing public health nutrition. In the case of land and water use, few studies used metrics that are appropriate in a life-cycle context. Some metrics produce inherently biased results, which misinform about environmental impact. The limited evidence generally points to recommended diets having lower environmental impacts than typical diets, although not in every case. This is largely explained by the overconsumption of food energy associated with average diets, which is also a major driver of obesity. A shared-knowledge framework is identified as being needed to guide future research on this topic. Until the evidence base becomes more complete, commentators on sustainable diets should not be quick to assume that a dietary strategy to reduce overall environmental impact can be readily defined or recommended.

A Systematic Review of the Measurement of Sustainable Diets

Sustainability has become an integral consideration of the dietary guidelines of many countries in recent decades. However, a lack of clear metrics and a shared approach to measuring the multiple components of sustainable diets has hindered progress toward generating the evidence needed to ensure the credibility of new guidelines. We performed a systematic literature review of empirical research studies on sustainable diets to identify the components of sustainability that were measured and the methods applied to do so. Two independent reviewers systematically searched 30 databases and other sources with the use of a uniform set of search terms and a priori exclusion criteria. In total, 113 empirical studies were included in the final review. Nearly all of the studies were focused on high-income countries. Although there was substantial heterogeneity in the components of sustainability measured, the estimated greenhouse gas emissions (GHGEs) of various dietary patterns were by far most commonly measured (n = 71 studies). Estimating the GHGEs of foods through various stages of production, use, and recycling with the use of the Life Cycle Assessment approach was the most common method applied to measure the environmental impacts of diets (n = 49 studies). Many components of sustainable diets identified in existing conceptual frameworks are disproportionately underrepresented in the empirical literature, as are studies that examine consumer demand for sustainable dietary alternatives. The emphasis in the literature on high-income countries also overlooks the production and dietary alternatives most relevant to low- and middle-income countries. We propose 3 methodological and measurement approaches that would both improve the global relevance of our understanding of sustainable diets and attend more completely to the existing multidimensional, multiscale conceptual framing of sustainable diets.