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.

Towards a sustainable diet combining economic, environmental and nutritional objectives

Foods consumed and dietary patterns are strong determinants of health status. Diet and nutrition have a key role in health promotion and maintenance during the entire lifetime, but what we choose to eat and drink greatly affects the environmental impact on ecosystems as well as monetary resources. Some studies suggest that a healthy diet with a low environmental impact is not necessarily more expensive. This paper aims to identify a healthy, greener and cheaper diet based on current consumption patterns. Dietary information was collected from 104 young adults in the last year of high school in Parma (Italy). Diet was monitored with 7-day dietary records. Subsequently, food items were decoded to obtain nutritional, economic and environmental impact data. An optimization tool based on mathematical programming (Multi-Objective Linear Programming) was used to identify sustainable diet. Three different 7-day diets were identified, based on nutrition recommendations for the healthy Italian adult population, characterized by different targets and optimizing different impacts: first the diet at the lowest cost (Minimum Cost Diet - MCD), then the Environmentally Sustainable Diet (ESD) obtained by minimizing the three environmental indicators (CO2e emissions, H2O consumption and amount of land to regenerate the resources - m(2)). Finally, the Sustainable Diet (SD) was identified by integrating environmental and economic sustainability objectives. Lastly, suggestions and recommendations for communication campaigns and other interventions to achieve sustainable diet are suggested.

Dietary recommendations in Spain -affordability and environmental sustainability?

Global food demand is increasing due to population growth and dietary transitions, resulting from rising incomes, are associated with increased prevalence of non-communicable diseases. Improving the sustainability of the food sector is also critical for achieving the Sustainable Development Goals. This study assesses for the first time the greenhouse gases emissions (Carbon Footprint - CF), the water footprint (WF) and the cost of three omnivorous diets recommended in Spain due to their health benefits: the Mediterranean diet (MD), the Southern European Atlantic diet (SEAD) and the Spanish dietary guidelines (NAOS). Analysis was conducted using standard Life Cycle Assessment and WF methods together with current Spanish food price data. The dietary energy recommendation of the SEAD is greater than that of MD and NAOS (11 and 15% respectively), and SEAD also has greater animal source food content than the other two diets. SEAD has a concomitantly higher CF, WF and cost scores in comparison with MD (+30%, +23% and +21% respectively) and NAOS (+15%, +9% and +21% respectively). Adjusting recommendations to meet the suggested Spanish adult dietary energy of 2228 kcal.capita^-1.day^-1 changed the environmental profiles of the diets and the NAOS has the highest environmental impact. However, the isocaloric diets had approximately the same cost. Analysis of the WF of the diets identified the major contribution of precipitation (the green WF) to the overall WF (88% of the total) and the significant contribution of animal-source foods to dietary WF. Regardless of the dietary scenario, better scores were identified for the Spanish recommendations analysed than those reported for other healthy diets identified in Europe. Differences in the recommended intake levels of certain food groups, cooking techniques and the origin of food products are behind these results. Environmental indicators should be considered alongside nutrition and health metrics when defining national dietary guidelines. Supporting citizens to follow healthy and environmentally-friendly dietary recommendations through, among other things, information campaigns and nutritional education programmes is essential. It is recommended the incorporation not only of health, but also of environmental indicators of these dietary options in the national dietary guidelines, as well as implementation of information campaigns and nutritional education programs among citizens to promote their adhesion since balanced dietary habits rich on plant-based products and low on animal-based ones involve multiple health and environmental benefits.

Towards an environmentally sustainable and healthy Atlantic dietary pattern: Life cycle carbon footprint and nutritional quality

Production and consumption of food has a significant effect on climate change. The effect of different consumption habits on the environment should not be under estimated, as there are different studies that mention the environmental impact associated with different foods, especially those of animal origin. The analysis of the Atlantic diet (AD), as the most common dietary pattern in Northwestern Spain, serves as an example of a diet with a high consumption of local, fresh and seasonal products, home cooking and low-processed foods. The evaluation was carried out by quantifying the carbon footprint following the Life Cycle Analysis methodology and identifying its nutritional quality according to the value of the Nutrient-rich Dietary index (NRD9.3.). According to the main results, the consumption of livestock products and shellfish is responsible for most GHG emissions (70% of the total). The basic ingredients of the AD, such as vegetables and legumes, make a relatively minor contribution (with an impact of 30% of the total) to the total carbon footprint of 3.01 kg CO₂eq·person^-1·day^-1. As regards nutritional quality, AD has a high nutritional score (474), mainly due to the low intake of sodium, added sugars and saturated fats (nutrients to be limited in healthy diets). In general, both the carbon footprint and the nutritional index score are consistent with those of other studies on the Mediterranean diet, which has been recognised as beneficial. Therefore, it can be concluded that the AD may be recommended from a nutritional and environmental point of view, mainly due to the high intake of fish and vegetables. The communication of this valuable environmental and nutritional information to consumers should be taken into account when considering strategic actions for the adoption of healthy and sustainable dietary patterns.

Adherence to the EAT-Lancet diet, genetic susceptibility, and risk of type 2 diabetes in Swedish adults

BACKGROUND AND AIMS

In 2019, the EAT-Lancet Commission proposed a mainly plant-based diet that nurtures human health and supports environmental sustainability. However, its association with type 2 diabetes (T2D) has not been widely studied, and it remains unclear whether genetic susceptibility for T2D can modify this association. The aim was therefore to investigate the association between the EAT-Lancet diet and risk of T2D and assess whether the association differs by the genetic predisposition to T2D.

METHODS

A total of 24,494 participants from the Malmö Diet and Cancer study were analyzed. Dietary intake was assessed using a modified diet history methodology, and an EAT-Lancet diet index (range from 0 to 42 points) was constructed based on the EAT-Lancet reference diet. National and local registers were used to identify T2D cases during follow-up. Cox proportional hazards regression model was applied to estimate the association between the EAT-Lancet diet index and risk of T2D. Genetic predisposition to T2D was captured based on 116 single nucleotide polymorphisms.

RESULTS

During a median of 24.3 years of follow-up, 4197 (17.1 %) T2D cases were documented. Compared with those with the lowest adherence to the EAT-Lancet diet (≤13 points), participants who had the highest adherence (≥23 points) showed an 18 % (95 % CI: 4 %-30 %) lower risk of T2D (P for trend <0.01). There was no significant multiplicative interaction between genetic predisposition to T2D and the EAT-Lancet diet index (P = 0.59). Also, no significant additive interaction between the genetic risk and the EAT-Lancet diet was seen (P = 0.44). The highest risk was observed among the 22.9 % of the individuals with high genetic risk and low EAT-Lancet diet score (HR = 1.79; 95 % CI: 1.63, 1.96).

CONCLUSIONS

Our findings indicate that high adherence to the EAT-Lancet diet was associated with decreased risk of incident T2D among people with different genetic risks.

Diet shift: Considering environment, health and food culture

Most studies have suggested that dietary choices have effects on both the environment and human health; however, they have ignored food culture, which is both an "independent variable" and a "dependent variable" of diet choice. The purpose of this study is to explore a diet optimization path that meets nutritional needs and has little impact on the environment, while respecting the local food culture to a large extent. We took China's Xinjiang Uygur autonomous region (hereinafter referred to as "Xinjiang") as the case area because Xinjiang is a multiethnic region with a unique food culture characterized by a high proportion of mutton in meat. According to the study's calculation, the current diet in Xinjiang has a high carbon footprint (CF), water footprint (WF) and ecological footprint (EF) and does not present the nutritional structure of a balanced diet. Considering the trade-offs among environmental carrying capacity, health and food culture is the challenge of changing the local food structure. With the method of multi-objective optimization, we propose "optimal diets", which show potential for mitigating environmental impacts and improving the state of health. Most importantly, one of the optimized diets is most desirable because it considers the preservation of the existing food culture. This study demonstrates the feasibility of providing a route for diet transformation that has double benefits regarding the environment and health, or even triple benefits regarding the environment, health and cultural acceptability.

Affordability of current, and healthy, more equitable, sustainable diets by area of socioeconomic disadvantage and remoteness in Queensland: insights into food choice

Background

Poor diet is the leading preventable risk factor contributing to the burden of disease globally and in Australia, and is inequitably distributed. As the price of healthy foods is a perceived barrier to improved diets, evidence on the cost and affordability of current (unhealthy) and recommended (healthy, more equitable and sustainable) diets is required to support policy action.

Methods

This study applied the Healthy Diets ASAP (Australian Standardised Affordability and Pricing) methods protocol to measure the cost, cost differential and affordability of current and recommended diets for a reference household in Queensland, Australia. Food prices were collected in 18 randomly selected locations stratified by area of socioeconomic disadvantage and remoteness. Diet affordability was calculated for three income categories.

Results

Surprisingly, recommended diets would cost 20% less than the current diet in Queensland as a whole. Households spent around 60% of their food budget on discretionary choices (that is, those not required for health that are high in saturated fat, added sugar, salt and/or alcohol). Queensland families would need to spend around 23% of their income on recommended diets. However, recommended diets would not be affordable in low socioeconomic or very remote areas, costing 30 and 35% of median household income respectively. The government supplements due to the SARS-CoV-2 pandemic would improve affordability of recommended diets by 29%.

Conclusions

Study findings highlight that while price is one factor affecting consumer food choice, other drivers such as taste, convenience, advertising and availability are important. Nevertheless, the study found that recommended diets would be unaffordable in very remote areas, and that low-income families are likely experiencing food stress, irrespective of where they live in Queensland. Policy actions, such as increasing to 20% the current 10% tax differential between basic healthy, and unhealthy foods in Australia, and supplementing incomes of vulnerable households, especially in remote areas, are recommended to help improve diet equity and sustainability, and health and wellbeing for all.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01481-8.

Dietary recommendations in Spain -affordability and environmental sustainability?

Global food demand is increasing due to population growth and dietary transitions, resulting from rising incomes, are associated with increased prevalence of non-communicable diseases. Improving the sustainability of the food sector is also critical for achieving the Sustainable Development Goals. This study assesses for the first time the greenhouse gases emissions (Carbon Footprint - CF), the water footprint (WF) and the cost of three omnivorous diets recommended in Spain due to their health benefits: the Mediterranean diet (MD), the Southern European Atlantic diet (SEAD) and the Spanish dietary guidelines (NAOS). Analysis was conducted using standard Life Cycle Assessment and WF methods together with current Spanish food price data. The dietary energy recommendation of the SEAD is greater than that of MD and NAOS (11 and 15% respectively), and SEAD also has greater animal source food content than the other two diets. SEAD has a concomitantly higher CF, WF and cost scores in comparison with MD (+30%, +23% and +21% respectively) and NAOS (+15%, +9% and +21% respectively). Adjusting recommendations to meet the suggested Spanish adult dietary energy of 2228 kcal.capita-1.day-1 changed the environmental profiles of the diets and the NAOS has the highest environmental impact. However, the isocaloric diets had approximately the same cost. Analysis of the WF of the diets identified the major contribution of precipitation (the green WF) to the overall WF (88% of the total) and the significant contribution of animal-source foods to dietary WF. Regardless of the dietary scenario, better scores were identified for the Spanish recommendations analysed than those reported for other healthy diets identified in Europe. Differences in the recommended intake levels of certain food groups, cooking techniques and the origin of food products are behind these results. Environmental indicators should be considered alongside nutrition and health metrics when defining national dietary guidelines. Supporting citizens to follow healthy and environmentally-friendly dietary recommendations through, among other things, information campaigns and nutritional education programmes is essential. It is recommended the incorporation not only of health, but also of environmental indicators of these dietary options in the national dietary guidelines, as well as implementation of information campaigns and nutritional education programs among citizens to promote their adhesion since balanced dietary habits rich on plant-based products and low on animal-based ones involve multiple health and environmental benefits.

Do Europeans consider sustainability when making food choices? A survey of Polish city-dwellers

Objective

To obtain a better insight into the conceptualization of sustainable consumption among consumers with special focus on food choice determinants. Previous studies show that people present positive attitude towards sustainable diet while their everyday food choices do not follow sustainable diet rules.

Design

A structured questionnaire was designed and data were collected via computer-assisted telephone interview among a random group (n 600) of city-dwellers. Quota sampling was used in proportion to the city population. Cluster analysis (k-means method) was applied to identify consumer segments according to the determinants of food choices. Consumer segments were identified using one-way ANOVA with post hoc Duncan comparison of mean scores and cross-tabulation with χ². The Friedman test was applied to identify enablers and barriers of sustainable food choices.

Setting

Cities in Mazovia, the best developed, central region of Poland.

Participants

Adults (21–70 years old).

Results

Consumers are not familiar with the concept of sustainability and are not able to define it adequately. Only 6 % of the studied population indicated that sustainable consumption is connected with nutrition which has possibly less impact on the environment. Three segments of consumers were distinguished regarding their attitude to food choice determinants adequate to sustainable diet: Non-Adopters (17 %), Emergents (32 %), Adopters (51 %). Desire to improve health by decreasing body weight was the main driver for sustainable food choices, while prices were the main limitation.

Conclusions

Knowledge dissemination on sustainability issues is needed to empower consumers to make more sustainable food choices and to make public health and food policy measures more effective.

Sustainable diet policy development: implications of multi-criteria and other approaches, 2008-2017

The objective of the present paper is to draw lessons from policy development on sustainable diets. It considers the emergence of sustainable diets as a policy issue and reviews the environmental challenge to nutrition science as to what a 'good' diet is for contemporary policy. It explores the variations in how sustainable diets have been approached by policy-makers. The paper considers how international United Nations and European Union (EU) policy engagement now centres on the 2015 Sustainable Development Goals and Paris Climate Change Accord, which require changes across food systems. The paper outlines national sustainable diet policy in various countries: Australia, Brazil, France, the Netherlands, Qatar, Sweden, UK and USA. While no overarching common framework for sustainable diets has appeared, a policy typology of lessons for sustainable diets is proposed, differentiating (a) orientation and focus, (b) engagement styles and (c) modes of leadership. The paper considers the particularly tortuous rise and fall of UK governmental interest in sustainable diet advice. Initial engagement in the 2000s turned to disengagement in the 2010s, yet some advice has emerged. The 2016 referendum to leave the EU has created a new period of policy uncertainty for the UK food system. This might marginalise attempts to generate sustainable diet advice, but could also be an opportunity for sustainable diets to be a goal for a sustainable UK food system. The role of nutritionists and other food science professions will be significant in this period of policy flux.

Which diet has the lower water footprint in Mediterranean countries?

The Mediterranean region is increasingly water scarce, with the food system being the largest driver of water use. We calculate the water resources related to food consumption in nine major Mediterranean countries, by means of the water footprint (WF), for the existing situation (period 2011-2013) as well as the Mediterranean and EAT-Lancet diets. We account for different food intake requirements according to gender and six age groups. These nine countries - Spain, France, Italy, Greece, Turkey, Egypt, Tunisia, Algeria and Morocco - represent 88% of the population of all countries bordering the Mediterranean. As first major observation, we find that the EAT-Lancet diet, a scientifically optimised diet for both nutrition and certain environmental indicators, requires less water resources than the Mediterranean diet, a culturally accepted diet within the region. In terms of water resources use, adherence to the former is thus more beneficial than adherence to the latter. As second major observation, we find that the EAT-Lancet diet reduces the current WF for all nations consistently, within the range -17% to -48%, whereas the Mediterranean diet reduces the WF of the European countries, Turkey, Egypt and Morocco within the range of -4% to -35%. For the Maghreb countries Tunisia and Algeria, the Mediterranean diet WF is slightly higher compared to the current WF and the proportions of food product groups differ. Such dietary shifts would be important parts of the solution to obtain the sustainable use of water resources in Mediterranean countries.

Choosing a healthy and sustainable diet: A three-level approach for understanding the drivers of the Italians' dietary regime over time

Dietary patterns play key roles in health promotion and in preserving the environment. A growing number of studies show the importance of individual factors on food consumption choices, such as socio-economic status, lifestyle variables and contextual and social factors that characterize the geographical area in which individuals reside. The Mediterranean Diet is a sustainable diet that respects the environment, thus reducing per capita emissions from food production in respect to less sustainable diet. The aim of this paper is to determine the Italians' prevailing food patterns using a composite indicator and to identify which factors determine a higher adherence to the Mediterranean Diet in Italy. By using 15 waves of the ISTAT "Aspect of Daily Life" survey, we constructed an original data set and referred to the multilevel approach which enabled us to distinguish between temporal and cross-sectional effects thus providing valuable insights to policy makers and stakeholders in order to promote the Mediterranean Diet and reap environmental and public health. The results show that education plays an important role in determining food consumption behavior while the tendency to practice sports on a regular basis and to have breakfast and lunch at home positively influence people's adherence to this diet.

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.

Do young adults value sustainable diet practices? Continuity in values from adolescence to adulthood and linkages to dietary behaviour

OBJECTIVE

To describe continuity over time in reports of valuing sustainable diet practices and investigate relationships between values, household meal behaviours and dietary intake.

DESIGN

Observational study. Participant ratings of how important it is for food to be produced as organic, not processed, locally grown and not GM were categorized to represent whether they valued (very/somewhat important) or did not value (a little/not at all important) each practice. Diet quality markers (e.g. fruit servings) were based on an FFQ.

SETTING

Mailed and online surveys.

PARTICIPANTS

Young adults (n 1620; 58 % female, mean age 31 (sd 1·6) years) who were participating in Project EAT (Eating and Activity among Teens and Young Adults) and responded to follow-up surveys in 2003-2004 and 2015-2016.

RESULTS

One-third (36·1 %) of participants reported valuing <2 practices at both assessments; 11·1 and 34·5 % respectively reported valuing ≥2 practices in 2003-2004 only and in 2015-2016 only; 18·3 % reported valuing ≥2 practices at both assessments. Regression models including demographics, parental status and vegetarian status showed that valuing ≥2 practices was associated with preparation of meals with vegetables at least a few times/week, less frequent purchase of family meals from fast-food restaurants, and higher diet quality in 2015-2016. For example, those who valued ≥2 practices consumed nearly one full vegetable serving more than other young adults on an average day and part of this difference was specifically associated with intake of dark green and red/orange vegetables.

CONCLUSIONS

Addressing the sustainability of food choices as part of public health messaging may be relevant for many young adults.

Animal board invited review: Animal agriculture and alternative meats - learning from past science communication failures

Sustainability discussions bring in multiple competing goals, and the outcomes are often conflicting depending upon which goal is being given credence. The role of livestock in supporting human well-being is especially contentious in discourses around sustainable diets. There is considerable variation in which environmental metrics are measured when describing sustainable diets, although some estimate of the greenhouse gas (GHG) emissions of different diets based on varying assumptions is commonplace. A market for animal-free and manufactured food items to substitute for animal source food (ASF) has emerged, driven by the high GHG emissions of ASF. Ingredients sourced from plants, and animal cells grown in culture are two approaches employed to produce alternative meats. These can be complemented with ingredients produced using synthetic biology. Alternative meat companies promise to reduce GHG, the land and water used for food production, and reduce or eliminate animal agriculture. Some CEOs have even claimed alternative meats will 'end world hunger'. Rarely do such self-proclamations emanate from scientists, but rather from companies in their efforts to attract venture capital investment and market share. Such declarations are reminiscent of the early days of the biotechnology industry. At that time, special interest groups employed fear-based tactics to effectively turn public opinion against the use of genetic engineering to introduce sustainability traits, like disease resistance and nutrient fortification, into global genetic improvement programs. These same groups have recently turned their sights on the 'unnaturalness' and use of synthetic biology in the production of meat alternatives, leaving agriculturists in a quandary. Much of the rationale behind alternative meats invokes a simplistic narrative, with a primary focus on GHG emissions, ignoring the nutritional attributes and dietary importance of ASF, and livelihoods that are supported by grazing ruminant production systems. Diets with low GHG emissions are often described as sustainable, even though the nutritional, social and economic pillars of sustainability are not considered. Nutritionists, geneticists, and veterinarians have been extremely successful at developing new technologies to reduce the environmental footprint of ASF. Further technological developments are going to be requisite to continuously improve the efficiency of animal source, plant source, and cultured meat production. Perhaps there is an opportunity to collectively communicate how innovations are enabling both alternative- and conventional-meat producers to more sustainably meet future demand. This could counteract the possibility that special interest groups who promulgate misinformation, fear and uncertainty, will hinder the adoption of technological innovations to the ultimate detriment of global food security.

An update on nutritional profile, phytochemical compounds, health benefits, and potential applications in the food industry of pulses seed coats: A comprehensive review

Pulses, as a sustainable source of nutrients, are an important choice for human diets, but vast quantities of seed coats generated in pulses processing are usually discarded or used as low-value ruminant feed. It has been demonstrated that pulses seed coats are excellent sources of dietary nutrients and phytochemicals with potential health benefits. With growing interest in the sustainable use of resources and the circular economy, utilization of pulses seed coats to recover these valuable components is a core objective for their valorization and an important step toward agricultural sustainability. This review comprehensively provides a comprehensive insight on the nutritional and phytochemical profiles presented in pulses seed coats and their health benefits obtained from the findings of in vitro and in vivo studies. Furthermore, in the food industry, pulses seed coats can be acted as potential food ingredients with nutritional, antioxidant and antimicrobial characteristics or as the matrix or active components of films for food packaging and edible coatings. A better understanding of pulses seed coats may provide a reference for increasing the overall added value and realizing the pulses' sustainable diets.

Food nitrogen footprint reductions related to a balanced Japanese diet

Dietary choices largely affect human-induced reactive nitrogen accumulation in the environment and resultant environmental problems. A nitrogen footprint (NF) is an indicator of how an individual's consumption patterns impact nitrogen pollution. Here, we examined the impact of changes in the Japanese diet from 1961 to 2011 and the effect of alternative diets (the recommended protein diet, a pescetarian diet, a low-NF food diet, and a balanced Japanese diet) on the food NF. The annual per capita Japanese food NF has increased by 55% as a result of dietary changes since 1961. The 1975 Japanese diet, a balanced omnivorous diet that reportedly delays senescence, with a protein content similar to the current level, reduced the current food NF (15.2 kg N) to 12.6 kg N, which is comparable to the level in the recommended protein diet (12.3 kg N). These findings will help consumers make dietary choices to reduce their impacts on nitrogen pollution.

The potential benefits of dietary shift in China: Synergies among acceptability, health, and environmental sustainability

The transition to a healthier diet recommended by national dietary guidelines in China may not achieve sufficient environmental benefits. This study assesses China's potential of transforming into a sustainable diet and the trade-offs among reducing food-related environmental impacts, improving nutritional quality and respecting eating habits. We used multi-objective optimization to build optimized scenarios, with the lowest environmental footprint and greatest acceptability (i.e., with the minimum departure from the currently observed diet) as optimization goals, and adequate macro- and micronutrient intake levels as constraints. In doing so, we assessed the actual benefits and synergies of reducing carbon footprint (CF), water footprint (WF), and ecological footprint (EF) and improving health and respecting dietary acceptance under the corresponding scenarios. The results show that CF, WF and EF can be reduced by up to 19%, 15% and 30% respectively, while satisfying nutritional constraints and achieving the minimum deviation from the current food combination. The greatest synergistic benefits for CF, WF and EF are achieved when the minimum CF is the optimization goal; the maximum synergistic benefits for the environment, health and acceptability are achieved when the CF is reduced by 10%. Our findings identify the trade-offs and synergies dietary changes considering nutritional benefits, environmental sustainability and acceptability, and reveal the challenges and opportunities for achieving such synergies.

The cost of eating more sustainable diets: A nutritional and environmental diet optimisation study

We aim to identify the dietary changes to improve nutrition and reduce diet-related greenhouse gas emission (GHGE) simultaneously in Brazil, taking into account the heterogeneity in food habits and prices across the country. Food consumption and prices were obtained from two nationwide surveys (n = 55,970 households and 34,003 individuals). Linear programming models were performed to design optimised diets most resembling the observed diets, and meeting different sets of constraints: (i) nutritional, for preventing chronic diseases and meeting nutrient adequacy; (ii) socio-cultural: by respecting food preferences; and (iii) environmental: by reducing GHGE by steps of 10%. Moving toward a diet that meets nutritional recommendations led to a 14% to 24% cost increase and 10% to 27% GHGE reduction, depending on the stringency of the acceptability constraints. Stronger GHGE reductions were achievable (up to about 70%), with greater departure from the current diet, but not achieving calcium and potassium goals. Diet cost increment tended to be mitigated with GHGE reduction in most models, along with reductions in red meat, chicken, eggs, rice, and high-fat sugar sodium foods.

Sustainability analysis of Finnish pre-schoolers' diet based on targets of the EAT-Lancet reference diet

Purpose

The EAT-Lancet reference diet is a healthy plant-based diet produced within planetary boundaries. To inform the food system transformation, we compared Finnish pre-schoolers’ food consumption with the reference diet’s food group targets.

Methods

Food record data for 3- to 6-year-old pre-schoolers were collected in the cross-sectional DAGIS survey. Ingredients of composite dishes were available in the data. In addition, we manually decomposed industrial products such as sausages and biscuits by estimating the shares of ingredients. We also estimated the consumption of added sugars and converted the consumption of dairy products into milk equivalents. We used usual intake modelling to estimate the mean consumption and the proportion of children who met the reference diet’s targets. We set the target amounts separately for 3- to 4-year-olds and 5- to 6-year-olds in grams by proportioning the published target amounts (assuming a 2500 kcal diet) to the children’s mean reported energy intake.

Results

For both age groups (3- to 4-year-olds, n = 460; 5- to 6-year-olds, n = 402), the daily mean consumption of whole grains, vegetables, legumes, nuts, and unsaturated oils was below targets, whereas the consumption of red meat, dairy foods, tubers, and added sugars was above targets. The consumption of fruit and fish was in line with targets.

Conclusion

To comply with the reference diet’s targets, major changes in the diets of Finnish children are needed. The key food groups targeted for higher consumption are whole grains and legumes and targeted for lower consumption red meat and dairy products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02672-3.

Adherence to the EAT-Lancet sustainable reference diet and cardiometabolic risk profile: cross-sectional results from the ELSA-Brasil cohort study

PURPOSE

The EAT-Lancet Commission released a reference sustainable diet to improve human health and respect the planetary boundaries. The Planetary Health Diet Index (PHDI) was developed with the purpose of evaluate the adherence to this reference diet. The aim of the present study was to evaluate the association between adherence to the EAT-Lancet diet with cardiometabolic risk profile.

METHODS

We used the cross-sectional baseline data from 14,155 participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter ongoing cohort study. Dietary data were collected using a 114-item validated food frequency questionnaire. The PHDI was used to assess the adherence to the EAT-Lancet diet. It consists of 16 components and the total score can range from 0 to 150 points. Linear, logistic and quasi-Poisson regression models were built to evaluate the associations between PHDI and the outcomes.

RESULTS

Individuals with higher adherence to EAT-Lancet diet (PHDI, 5th quintile) had lower values for systolic blood pressure (β - 0.84; 95% CI - 1.66: - 0.01), diastolic blood pressure (β - 0.70; 95% CI - 1.24: - 0.15), total cholesterol (β - 3.15; 95% CI - 5.30: - 1.01), LDL-c (β - 4.10; 95% CI - 5.97: -  2.23), and non-HDL-cholesterol (β - 2.57; 95% CI - 4.62: - 0.52). No association was observed for HDL-c, triglycerides and HOMA-IR.

CONCLUSIONS

Our results indicate that higher adherence to the EAT-Lancet diet is associated with lower levels of blood pressure, total cholesterol, LDL-c, and non-HDL-c.

Consuming sustainable seafood: guidelines, recommendations and realities

OBJECTIVE

Encouraging people to eat more seafood can offer a direct, cost-effective way of improving overall health outcomes. However, dietary recommendations to increase seafood consumption have been criticised following concern over the capacity of the seafood industry to meet increased demand, while maintaining sustainable fish stocks. The current research sought to investigate Australian accredited practising dietitians' (APD) and public health nutritionists' (PHN) views on seafood sustainability and their dietary recommendations, to identify ways to better align nutrition and sustainability goals.

DESIGN

A self-administered online questionnaire exploring seafood consumption advice, perceptions of seafood sustainability and information sources of APD and PHN. Qualitative and quantitative data were collected via open and closed questions. Quantitative data were analysed with χ 2 tests and reported using descriptive statistics. Content analysis was used for qualitative data.

SETTING

Australia.

SUBJECTS

APD and PHN were targeted to participate; the sample includes respondents from urban and regional areas throughout Australia.

RESULTS

Results indicate confusion around the concept of seafood sustainability and where to obtain information, which may limit health professionals' ability to recommend the best types of seafood to maximise health and sustainability outcomes. Respondents demonstrated limited understanding of seafood sustainability, with 7·5 % (n 6/80) satisfied with their level of understanding.

CONCLUSIONS

Nutrition and sustainability goals can be better aligned by increasing awareness on seafood that is healthy and sustainable. For health professionals to confidently make recommendations, or identify trade-offs, more evidence-based information needs to be made accessible through forums such as dietetic organisations, industry groups and nutrition programmes.

Association between the socio-economic status of households and a more sustainable diet

OBJECTIVE

A sustainable diet is an affordable diet with low environmental impact, high food security and sufficient healthiness. The present study aimed to assess the correlation between the socio-economic status of households and a sustainable diet.

DESIGN

The food basket and socio-economic data of Iranian households were evaluated during 2016-2018. The households were classified based on the sustainability of their diet by determining the dietary carbon footprint, dietary water footprint, lower dietary costs of the household than the median and a higher dietary quality index than the median. Logistic regression was used with four models to calculate the OR of a more sustainable diet as the dependent variable regarding the different quartiles of socio-economic status (SES) as the independent variable.

SETTING

Iran.

PARTICIPANTS

Iranian households (n 102 303), nationally representative, were studied.

RESULTS

Lower SES was associated with the higher OR of a sustainable diet (OR: 0·90; (95 % CI 0·87, 0·91)). Higher quartiles of SES compared with the lower SES group indicated the higher energy intake and consumption of more dairies, meat, poultry, fish, eggs, legumes, nuts and fruits, as well as the lower intake of bread, cereal, rice and pasta.

CONCLUSION

In countries such as Iran, where nutrition transition occurs rapidly, better economic and social levels in the populations with a higher SES are associated with increased energy intake and higher consumption of animal-based foods, which decreases sustainable diets compared with the groups with a lower SES.

An assessment of the water use associated with Australian diets using a planetary boundary framework

OBJECTIVE

Agriculture accounts for around 70 % of global freshwater withdrawals. As such, the food system has been identified as a critical intervention point to address water scarcity. Various studies have identified dietary patterns that contribute less to water scarcity. However, it is unclear what level of reduction is necessary to be considered sustainable. The pursuit of unnecessarily aggressive reductions could limit dietary diversity. Our objective was to assess the sustainability of water use supporting Australian dietary habits and the adequacy of current dietary guidelines.

DESIGN

Dietary intake data were obtained from the National Nutrition and Physical Activity component of the Australian Health Survey. For each individual daily diet, the water scarcity footprint was quantified, following ISO14046:2014, as well as a diet quality score. Water scarcity footprint results were compared with the planetary boundary for freshwater use downscaled to the level of an individual diet.

SETTING

Australia.

PARTICIPANTS

9341 adults participating in the Australian Health Survey.

RESULTS

Dietary water scarcity footprints averaged 432·6 L-eq (95 % CI 432·5, 432·8), less than the 695 litres/person per d available to support the current global population of 7·8 billion, and the 603 litres/person per d available for a future population of 9 billion. Diets based on the Australian Dietary Guidelines required 521 L-eq/d, or 379 L-eq/d with lower water scarcity footprint food choices.

CONCLUSIONS

Diets based on the Australian Dietary Guidelines were found to be within the freshwater planetary boundary. What is needed in Australia is greater compliance with dietary guidelines.

Hepatic Fatty Acid and Transcriptome Profiles during the Transition from Vegetable- to Fish Oil-Based Diets in Rainbow Trout (Oncorhynchus mykiss)

A finishing diet strategy is effective at increasing fillet long-chain n-3 fatty acid content in fish consuming sustainable plant oil-based diets. This study investigates the outcomes of a fish oil finishing diet upon the hepatic fatty acid and transcriptome profile in rainbow trout (Oncorhynchus mykiss). Fish were placed on one of three feeding treatments: (1) FO: a fish oil (FO) diet for 20 weeks, (2) VO/FO: a vegetable oil (VO) diet during weeks 1-12 then the FO diet for 8 weeks, or (3) VO/fd/FO: the VO diet between weeks 1-12, 2 weeks of feed deprivation, then the FO diet for 6 weeks. Hepatic fatty acid and transcriptome profiles were analyzed at week 12, 14, and 20. Hepatic fatty acid profiles at week 12 were similar to dietary profiles; transcriptomic analyses indicated 131 differentially regulated genes (DEG) between VO- and FO-fed fish, characterized by VO-induced up-regulation of cholesterol and long-chain fatty acyl-CoA synthesis and oxidation-reduction processes. At week 14, the hepatic fatty acid profile was similar between VO/FO and FO, although concentrations of 18:3n-3 remained higher in the VO/FO group. Thirty-three DEG were detected at week 14 with enrichment of genes associated with extracellular matrix assembly, supporting liver remodeling during the early finishing diet period. Only five DEG were detected at week 20 between VO/FO and FO. Collectively, these findings suggest that it takes several weeks for liver to reach a homeostatic state, even after the hepatic fatty acid equilibration following a finishing diet.