Sustainable diets for the future: Can we contribute to reducing greenhouse gas emissions by eating a healthy diet?

Low-carbon diets across diverse dietary patterns: Addressing population heterogeneity under constrained optimization

Mathematical optimization is a useful tool for modeling diets that fulfill requirements for health and environmental sustainability, however, population-based optimization approaches fail to account for underlying dietary diversity in populations. This study proposes a methodological approach to consider diverse dietary intake patterns in mathematical optimization of nutritionally adequate low-carbon diets and investigates the differences between different population groups, along with trade-offs between greenhouse gas emission (GHGE) reduction and the inconvenience of dietary changes required to achieve optimized diets. A k-means clustering analysis was applied to individual dietary intake data from Denmark, which resulted in four clusters with different dietary patterns. This was followed by quadratic programming, wherein the total dietary changes required from the observed diet within each cluster were used as a proxy for consumer inconvenience (i.e., "inconvenience index") and were minimized while fulfilling nutrient constraints and incrementally tightened GHGE constraints. Across clusters, a steep increase of the inconvenience index was observed at GHGE levels below approximately 3 kg CO2e/10 MJ, corresponding to GHGE reductions of 24-36 % in different clusters. In all clusters, the optimized diets with nutritional and GHGE constraints showed common traits of increased content of cereals and starches, eggs, and fish and decreased amounts of beef and lamb, cheese, animal-based fats, and alcoholic beverages, but differences across clusters were also observed, maintaining characteristics of the clusters' baselines. When additional health-based targets for food amounts were applied as constraints, the optimized diets converged towards the same type of diet. The total inconvenience of dietary changes required to fulfill constraints differed between clusters, indicating that specific sub-populations may be more effective targets for dietary transition. The method has potential for future integration of more sustainability aspects and different consumer preferences.

Developing and testing personalised nutrition feedback for more sustainable healthy diets: the MyPlanetDiet randomised controlled trial protocol

PURPOSE

Agriculture and food production contribute to climate change. There is mounting pressure to transition to diets with less environmental impact while maintaining nutritional adequacy. MyPlanetDiet aimed to reduce diet-related greenhouse gas emissions (GHGE) in a safe, nutritionally adequate, and acceptable manner. This paper describes the trial protocol, development, and testing of personalised nutrition feedback in the MyPlanetDiet randomised controlled trial (RCT).

METHODS

MyPlanetDiet was a 12-week RCT that provided standardised personalised nutrition feedback to participants based on new sustainable healthy eating guidelines (intervention) or existing healthy eating guidelines (control) using decision trees and corresponding feedback messages. To test the personalised nutrition feedback, we modelled a sample of 20 of the MyPlanetDiet participants baseline diets. Diets were modelled to adhere to control and intervention decision trees and feedback messages. Modelled nutrient intakes and environmental metrics were compared using repeated measure one-way analysis of covariance.

RESULTS

Intervention diets had significantly lower (p < 0.001) diet-related GHGE per 2500 kilocalories (kcal) (4.7 kg CO2-eq) relative to control (6.6 kg CO2-eq) and baseline (7.1 kg CO2-eq). Modelled control and intervention diets had higher mean daily intakes of macronutrients (carbohydrates, fibre, and protein) and micronutrients (calcium, iron, zinc, and iodine). Modelled control and intervention diets had lower percent energy from fat and saturated fat relative to baseline.

CONCLUSIONS

Adherence to the MyPlanetDiet personalised nutrition feedback would be expected to lead to better nutrient intakes and reduced diet-related GHGE. The MyPlanetDiet RCT will test the effectiveness and safety of personalised feedback for a more sustainable diet.

TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

Clinical trials registration number: NCT05253547, 23 February 2022.

The planet on our plates: approaches to incorporate environmental sustainability within food-based dietary guidelines

For many decades, food-based dietary guidelines (FBDGs) were only health-oriented. This changed post-2009 when gradually, an increasing number of countries began to include environmental sustainability considerations in their guidelines. International organisations such as the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have stated that governments should include environmental sustainability in future FBDGs. However, methodologies on how this should be done are lacking. Therefore, through workshops and discussions with experts, we analysed a selection of methodologies and classified them into six groups: (1) health first; (2) additional advice; (3) demonstrating synergies; (4) modelling impact; (5) combining strategies; (6) systems first. We then assessed how innovative each approach was and their potential for transformative impact. Of the 6 approaches investigated, only approaches 5 and 6 could be considered as disruptive innovations and leading to major changes. Adding environmental sustainability into FBDGs is a policy innovation and has become a debate between old and new multi-criteria guidelines for eating. With the addition of environmental sustainability in FBDGS, a new or emerging set of multi-criteria guidelines for judging food are being proposed that challenges past norms and governance. Today, there is growing scientific consensus that diets that are good for human health are also good for the environment. There is also a growing recognition that food system change is inevitable and desirable. We see this as a positive opportunity to collaborate on FBDGs that are more appropriate for the 21st century and ambitious enough to meet the environmental challenges at hand.

Effect of Sustainably Sourced Protein Consumption on Nutrient Intake and Gut Health in Older Adults: A Systematic Review

Diet is integral to the healthy ageing process and certain diets can mitigate prolonged and deleterious inflammation. This review aims to assess the impact of diets high in sustainably sourced proteins on nutrient intake, gut, and age-related health in older adults. A systematic search of the literature was conducted on 5 September 2023 across multiple databases and sources. Studies assessing sustainably sourced protein consumption in community dwelling older adults (≥65 years) were included. Risk of bias (RoB) was assessed using 'RoB 2.0' and 'ROBINS-E'. Narrative synthesis was performed due to heterogeneity of studies. Twelve studies involving 12,166 older adults were included. Nine studies (n = 10,391) assessed habitual dietary intake and had some RoB concerns, whilst three studies (n = 1812), two with low and one with high RoB, conducted plant-based dietary interventions. Increased adherence to sustainably sourced diets was associated with improved gut microbial factors (n = 4640), healthier food group intake (n = 2142), and increased fibre and vegetable protein intake (n = 1078). Sustainably sourced diets positively impacted on gut microbiota and healthier intake of food groups, although effects on inflammatory outcomes and health status were inconclusive. Future research should focus on dietary interventions combining sustainable proteins and fibre to evaluate gut barrier function and consider inflammatory and body composition outcomes in older adults.

Self-perceived food literacy in relation to the quality of overall diet and main meals: A cross-sectional study in Japanese adults

This cross-sectional study aimed to assess the relationship between self-perceived food literacy (SPFL) and quality of overall diet and main meals in Japanese adults. In total, 5998 adults aged 20-79 years were included in this analysis. The SPFL was assessed using the Japanese version of the 29-item Dutch SPFL scale (score range 1-5). Using validated dietary information, the Healthy Eating Index-2015 (HEI-2015) was calculated (score range 0-100). The mean SPFL was 3.18; the internal consistency of the overall scale was considered good (Cronbach's alpha: 0.80). The mean HEI-2015 for overall diet was 50.4. The SPFL was significantly and positively associated with the HEI-2015. Using multiple linear regression, one point increase of SPFL corresponded to an increase in HEI-2015 by a point of 4.8 for overall diet, 6.2 for breakfast, 4.6 for lunch, and 3.6 for dinner (all P < 0.0001). Six of the eight domains of SPFL (i.e., food preparation skills, resilience and resistance, healthy snack styles, examining food labels, healthy budgeting, and healthy food stockpiling) were significantly associated with the HEI-2015 for overall diet. When the HEI-2015 for each meal was examined, the domains showing significant associations with all three meals included food preparation skills, healthy snack styles, and healthy budgeting. The healthy food stockpiling was associated with the HEI-2015 for breakfast and lunch, but not dinner. The social and conscious eating and daily food planning were associated with the breakfast HEI-2015 only, with the resilience and resistance associated with the dinner HEI-2015 only. In conclusion, the SPFL was cross-sectionally associated with the quality of overall diet and main meals in Japanese adults. Further observation and intervention studies are needed to confirm the associations observed here.

Sociodemographic Trends in Planetary Health Diets among Nutrition Students in Türkiye: Bridging Classroom to Kitchen

This study aimed to investigate the effects of sociodemographic parameters on healthy and sustainable nutrition in nutrition students. This cross-sectional study was conducted with 601 students. Researchers administered questionnaire forms to gather sociodemographic information such as age, gender, geographical region, residence area, accommodation, BMI, and income level. Participants' 24 h dietary records were used to evaluate Healthy Eating Index-2020 (HEI-2020) and Planetary Health Diet Index (PHDI). The mean PHDI scores of the Marmara (53.4 ± 14.9), Aegean (58.2 ± 18.3), Mediterranean (55.3 ± 15.5), and Black Sea (55.5 ± 15.7) regions, which are the coastal regions of Türkiye, were significantly higher than for the Central Anatolia region (46.7 ± 15.1). The PHDI and HEI-2020 score means of students living in metropolitan cities and rural areas were significantly higher than those living in urban areas (p < 0.05). Being in the 20-25 years age group increased the probability of being in a lower PHDI group (AOR 1.82; 95% CI 1.07:3.12; p = 0.028). While a similar result was found in the 20-25 years age group for HEI-2020, income level and gender did not have a statistically significant effect on these scores. Since students' ages, geographical regions, and residence areas affect PHDI and HEI-2020, it is considered important to take these sociodemographic variables into consideration in guidelines and studies.

Impact of consuming an environmentally protective diet on micronutrients: a systematic literature review

BACKGROUND

A global move toward consumption of diets from sustainable sources is required to protect planetary health. As this dietary transition will result in greater reliance on plant-based protein sources, the impact on micronutrient (MN) intakes and status is unknown.

OBJECTIVE

Evaluate the evidence of effects on intakes and status of selected MNs resulting from changes in dietary intakes to reduce environmental impact. Selected MNs of public health concern were vitamins A, D, and B12, folate, calcium, iron, iodine, and zinc.

METHODS

We systematically searched 7 databases from January 2011 to October 2022 and followed the PRISMA guidelines. Eligible studies had to report individual MN intake and/or status data collected in free-living individuals from the year 2000 onward and environmental outcomes.

RESULTS

From the 10,965 studies identified, 56 studies were included, mostly from high-income countries (n = 49). Iron (all 56) and iodine (n = 20) were the most and least reported MNs, respectively. There was one randomized controlled trial (RCT) that also provided the only biomarker data, 10 dietary intake studies, and 45 dietary modeling studies, including 29 diet optimization studies. Most studies sought to reduce greenhouse gas emissions or intake of animal-sourced foods. Most results suggested that intakes of zinc, calcium, iodine, and vitamins B12, A, and D would decrease, and total iron and folate would increase in a dietary transition to reduce environmental impacts. Risk of inadequate intakes of zinc, calcium, vitamins A, B12 and D were more likely to increase in the 10 studies that reported nutrient adequacy. Diet optimization (n = 29) demonstrated that meeting nutritional and environmental targets is technically feasible, although acceptability is not guaranteed.

CONCLUSIONS

Lower intakes and status of MNs of public health concern are a potential outcome of dietary changes to reduce environmental impacts. Adequate consideration of context and nutritional requirements is required to develop evidence-based recommendations. This study was registered prospectively with PROSPERO (CRD42021239713).

Developing a novel optimisation approach for keeping heterogeneous diets healthy and within planetary boundaries for climate change

BACKGROUND AND OBJECTIVES

Current dietary habits have substantial negative impacts on the health of people and the planet. This study aimed to develop a novel approach for achieving health-promoting and climate-friendly dietary recommendations for a broad range of consumers.

SUBJECTS AND METHODS

Hierarchical clustering analysis was combined with linear programming to design nutritionally adequate, health-promoting, climate-friendly and culturally acceptable diets using Swedish national dietary data (n = 1797). Diets were optimised for the average consumption of the total population as well as for the dietary clusters.

RESULTS

Three dietary clusters were identified. All optimised diets had lower shares of animal-source foods and contained higher amounts of plant-based foods. These dietary shifts reduced climate impacts by up to 53% while leaving much of the diet unchanged. The optimised diets of the three clusters differed from the optimised diet of the total population. All optimised diets differed considerably from the food-group pattern of the EAT-Lancet diet.

CONCLUSIONS

The novel cluster-based optimisation approach was able to generate alternatives that may be more acceptable and realistic for a sustainable diet across different groups in the population.

Select dietary changes towards sustainability: Impacts on dietary profiles, environmental footprint, and cost

Healthy sustainable diets have the power to improve dietary intakes and environmental resource use. However, recommendations for improving food choices need to consider the effects of any changes across multiple dimensions of health, environmental sustainability, and dietary cost to promote long-lasting behaviour change. The aim of this study was to identify differences between original diets, and the diets that can be achieved through the implementation of select small dietary changes towards sustainability. Twelve hypothetical sustainable actions were investigated for the potential effects of these actions on dietary markers (protein, saturated fat, sugars, salt, iron, and calcium), environmental footprints (greenhouse gas emissions, freshwater withdrawals, and land use), and dietary cost. Dietary data from 1235 individuals, aged 19-94 years, participating in the UK National Diet and Nutrition Survey (2017/19) provided the original diet. Dietary changes were implemented as required by each sustainable action, and differences between the original diet and each new diet were investigated. Results revealed benefits to dietary markers and environmental characteristics from eleven sustainable actions (range: F(1,728) = 5.80, p < .001 to F(1,506) = 435.04, p < .001), but effects were stronger for some actions than for others. Greatest benefits for all three outcomes were found for actions which reduced meat consumption and/or replaced meat with pulses or eggs. The remaining sustainable actions tended to be beneficial for improving outcomes individually or to some degree. Our results demonstrate the possible impacts of a number of small sustainable dietary actions for dietary, environmental, and cost outcomes, and provide a hierarchy of actions based on benefit. Findings may facilitate dietary behaviours towards improved health, whilst also offering fruitful contributions towards environmental footprint targets in the UK.

Reducing meat and/or dairy consumption in adults: a systematic review and meta-analysis of effects on protein intake, anthropometric values, and body composition

CONTEXT

Consumers are increasingly encouraged to reduce meat and dairy consumption. However, few meta-analyses of randomized controlled trials (RCTs) on the effect of reducing meat and/or dairy on (absolute) protein intake, anthropometric values, and body composition are available.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effect of reducing meat and/or dairy consumption on (absolute) protein intake, anthropometric values, and body composition in adults aged ≥ 45 years.

DATA SOURCES

The MEDLINE, Cochrane CENTRAL, Embase, ClinicalTrials.gov, and International Clinical Trials Registry Platform databases were searched up to November 24, 2021.

DATA EXTRACTION

Randomized controlled trials reporting protein intake, anthropometric values, and body composition were included.

DATA ANALYSIS

Data were pooled using random-effects models and expressed as the mean difference (MD) with 95%CI. Heterogeneity was assessed and quantified using Cochran's Q and I2 statistics. In total, 19 RCTs with a median duration of 12 weeks (range, 4-24 weeks) and a total enrollment of 1475 participants were included. Participants who consumed meat- and/or dairy-reduced diets had a significantly lower protein intake than those who consumed control diets (9 RCTs; MD, -14 g/d; 95%CI, -20 to -8; I2 = 81%). Reducing meat and/or dairy consumption had no significant effect on body weight (14 RCTs; MD, -1.2 kg; 95%CI, -3 to 0.7; I2 = 12%), body mass index (13 RCTs; MD, -0.3 kg/m2; 95%CI, -1 to 0.4; I2 = 34%), waist circumference (9 RCTs; MD, -0.5 cm; 95%CI, -2.1 to 1.1; I2 = 26%), amount of body fat (8 RCTs; MD, -1.0 kg; 95%CI, -3.0 to 1.0; I2 = 48%), or lean body mass (9 RCTs; MD, -0.4 kg; 95%CI, -1.5 to 0.7; I2 = 0%).

CONCLUSION

Reduction of meat and/or dairy appears to reduce protein intake. There is no evidence of a significant impact on anthropometric values or body composition. More long-term intervention studies with defined amounts of meat and dairy are needed to investigate the long-term effects on nutrient intakes and health outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020207325.

Quantification and environmental impact of slaughter waste during its life cycle

Considering the lack of an in-depth and comprehensive study on slaughter waste quantification and its management, despite the growing demand for meat this study aims to quantify the slaughter waste generated in Mumbra, Thane, India, from the meat retail stores. The study also endeavors to find the composition of slaughter waste in municipal solid waste by employing the questionnaire survey method. The literature reviewed the published studies on the life cycle analysis of food products for global warming potential values for meat and vegetable products along with the vegetarian and non-vegetarian dietary patterns. In this study, it was observed that 55.93% of the population were non-vegetarian consumers and the composition of slaughter waste was 7% of total municipal solid waste disposed of in disposal sites resulting in greenhouse gas emission of 0.11 Gg CO2 Eq./year. The study presents the implementation of a biomethanation plant as a mitigation measure, along with an evaluation of the theoretical biogas potential and electricity generation capacity derived from slaughter waste, considering it as a potential feedstock. The outcomes of this study also highlight the necessity for further focused research in this specific area, aiming to increase consumer knowledge regarding the environmental impacts of meat-based diets. The finding of this study will help researchers and assists policymakers in facilitating effective management and understanding the scale of the emissions resulting from meat products and slaughter waste and identifying suitable mitigation approaches, and actively contributing to reducing the environmental footprint.

Moving towards more sustainable diets: Is there potential for a personalised approach in practice?

Discourse on the relationship between food production, healthy eating and sustainability has become increasingly prominent and controversial in recent years. Research groups often take one perspective when reporting on sustainable diets, and several often neglect considerations for the multiple aspects that make a diet truly sustainable, such as cultural acceptability, differences in nutritional requirements amongst the population and the efficiency of long-term dietary change. Plant-based diets are associated with lower greenhouse gas emissions (GHGEs) and have been linked with better health outcomes, including lower risk of diet-related chronic disease. However, foods associated with higher GHGE, such as lean red meat, fish and dairy, have beneficial nutritional profiles and contribute significantly to micronutrient intakes. Some research has shown that diets associated with lower GHGE can be less nutritionally adequate. Several countries now include sustainability recommendations in dietary guidelines but use vague language such as "increase" or "consume regularly" when referring to plant-based foods. General population-based nutrition advice has poor adherence and does not consider differences in nutritional needs. Although modelling studies show potential to significantly reduce environmental impact with dietary changes, personalising such dietary recommendations has not been studied. Adapting recommendations to the individual through reproducible methods of personalised nutrition has been shown to lead to more favourable and longer-lasting dietary changes compared to population-based nutrition advice. When considering sustainable healthy dietary guidelines, personalised feedback may increase the acceptability, effectiveness and nutritional adequacy of the diet. A personalised approach has the potential for delivering a new structure of more sustainable healthy food-based dietary guidelines. This review evaluates the potential to develop personalised sustainable healthy food-based dietary guidelines and discusses potential implications for policy and practice.

A multi-center prospective study of plant-based nutritional support in adult community-based patients at risk of disease-related malnutrition

Introduction

There is an emerging need for plant-based, vegan options for patients requiring nutritional support.

Methods

Twenty-four adults at risk of malnutrition (age: 59 years (SD 18); Sex: 18 female, 6 male; BMI: 19.0 kg/m2 (SD 3.3); multiple diagnoses) requiring plant-based nutritional support participated in a multi-center, prospective study of a (vegan suitable) multi-nutrient, ready-to-drink, oral nutritional supplement (ONS) [1.5 kcal/mL; 300 kcal, 12 g protein/200 mL bottle, mean prescription 275 mL/day (SD 115)] alongside dietary advice for 28 days. Compliance, anthropometry, malnutrition risk, dietary intake, appetite, acceptability, gastrointestinal (GI) tolerance, nutritional goal(s), and safety were assessed.

Results

Patients required a plant-based ONS due to personal preference/variety (33%), religious/cultural reasons (28%), veganism/reduce animal-derived consumption (17%), environmental/sustainability reasons (17%), and health reasons (5%). Compliance was 94% (SD 16). High risk of malnutrition ('MUST' score ≥ 2) reduced from 20 to 16 patients (p = 0.046). Body weight (+0.6 kg (SD 1.2), p = 0.02), BMI (+0.2 kg/m2 (SD 0.5), p = 0.03), total mean energy (+387 kcal/day (SD 416), p < 0.0001) and protein intake (+14 g/day (SD 39), p = 0.03), and the number of micronutrients meeting the UK reference nutrient intake (RNI) (7 vs. 14, p = 0.008) significantly increased. Appetite (Simplified Nutritional Appetite Questionnaire (SNAQ) score; p = 0.13) was maintained. Most GI symptoms were stable throughout the study (p > 0.06) with no serious adverse events related.

Discussion

This study highlights that plant-based nutrition support using a vegan-suitable plant-based ONS is highly complied with, improving the nutritional outcomes of patients at risk of malnutrition.

Exploring Benefits and Barriers of Plant-Based Diets: Health, Environmental Impact, Food Accessibility and Acceptability

Unhealthy dietary patterns are directly linked to the current Global Syndemic consisting of non-communicable diseases, undernutrition and climate change. The dietary shift towards healthier and more sustainable plant-based diets is essential. However, plant-based diets have wide intra differences; varying from vegan diets that totally exclude meat and animal products to traditional ones such as the Mediterranean diet and the new Nordic diet. It is acknowledged that plant-based diets may contribute simultaneously to improving population health as well as to decreasing the environmental impact of food systems. Evidence from cohort and randomized-controlled trials suggests that plant-based dietary patterns have beneficial effects on bodyweight control, cardiovascular health and diabetes prevention and treatment. On the other hand, micronutrient requirements may not be met, if some plant-based diets are not well-planned. Additionally, studies showed that lower consumption of meat and animal products results in lower environmental impacts. Consequently, plant-based diets could be a key factor to increase diet sustainability. This narrative review addresses the advantages of adherence to plant-based diets on human and planetary health considering strains and barriers to achieve this dietary transition, including cultural acceptability and affordability factors. Finally, potential intervention and policy recommendations are proposed, focusing on the update of current national food-based dietary guidelines.

Exploring healthy and climate-friendly diets for Danish adults: an optimization study using quadratic programming

Background

A transition to healthy and sustainable diets has the potential to improve human and planetary health but diets need to meet requirements for nutritional adequacy, health, environmental targets, and be acceptable to consumers.

Objective

The objective of this study was to derive a nutritionally adequate and healthy diet that has the least deviation possible from the average observed diet of Danish adults while aiming for a greenhouse gas emission (GHGE) reduction of 31%, corresponding to the GHGE level of the Danish plant-rich diet, which lays the foundation for the current healthy and sustainable food-based dietary guidelines (FBDGs) in Denmark.

Methods

With an objective function minimizing the departure from the average observed diet of Danish adults, four diet optimizations were run using quadratic programming, with different combinations of diet constraints: (1) nutrients only (Nutri), (2) nutrients and health-based targets for food amounts (NutriHealth), (3) GHGE only (GHGE), and finally, (4) combined nutrient, health and GHGE constraints (NutriHealthGHGE).

Results

The GHGE of the four optimized diets were 3.93 kg CO₂-eq (Nutri), 3.77 kg CO₂-eq (NutriHealth) and 3.01 kg CO₂-eq (GHGE and NutriHealthGHGE), compared to 4.37 kg CO₂-eq in the observed diet. The proportion of energy from animal-based foods was 21%-25% in the optimized diets compared to 34% in the observed diet and 18% in the Danish plant-rich diet. Moreover, compared to the average Danish diet, the NutriHealthGHGE diet contained more grains and starches (44 E% vs. 28 E%), nuts (+230%), fatty fish (+89%), eggs (+47%); less cheese (-73%), animal-based fats (-76%), total meat (-42%); and very limited amounts of ruminant meat, soft drinks, and alcoholic beverages (all-90%), while the amounts of legumes and seeds were unchanged. On average, the mathematically optimized NutriHealthGHGE diet showed a smaller deviation from the average Danish diet compared to the Danish plant-rich diet (38% vs. 169%, respectively).

Conclusion

The final optimized diet presented in this study represents an alternative way of composing a nutritionally adequate and healthy diet that has the same estimated GHGE as a diet consistent with the climate-friendly FBDGs in Denmark. As this optimized diet may be more acceptable for some consumers, it might help to facilitate the transition toward more healthy and sustainable diets in the Danish population.

Plant to animal protein ratio in the diet: nutrient adequacy, long-term health and environmental pressure

Background

Animal and plant protein sources have contrasting relationships with nutrient adequacy and long-term health, and their adequate ratio is highly debated.

Objective

We aimed to explore how the percentage of plant protein in the diet (%PP) relates to nutrient adequacy and long-term health but also to environmental pressures, to determine the adequate and potentially optimal %PP values.

Methods

Observed diets were extracted from the dietary intakes of French adults (INCA3, n = 1,125). Using reference values for nutrients and disease burden risks for foods, we modeled diets with graded %PP values that simultaneously ensure nutrient adequacy, minimize long-term health risks and preserve at best dietary habits. This multi-criteria diet optimization was conducted in a hierarchical manner, giving priority to long-term health over diet proximity, under the constraints of ensuring nutrient adequacy and food cultural acceptability. We explored the tensions between objectives and identified the most critical nutrients and influential constraints by sensitivity analysis. Finally, environmental pressures related to the modeled diets were estimated using the AGRIBALYSE database.

Results

We find that nutrient-adequate diets must fall within the ~15-80% %PP range, a slightly wider range being nevertheless identifiable by waiving the food acceptability constraints. Fully healthy diets, also achieving the minimum-risk exposure levels for both unhealthy and healthy foods, must fall within the 25-70% %PP range. All of these healthy diets were very distant from current typical diet. Those with higher %PP had lower environmental impacts, notably on climate change and land use, while being as far from current diet.

Conclusion

There is no single optimal %PP value when considering only nutrition and health, but high %PP diets are more sustainable. For %PP > 80%, nutrient fortification/supplementation and/or new foods are required.

Impact of Coronavirus Disease COVID-19 on the Relationship between Healthcare Expenditures and Sustainable Economic Growth

The coronavirus disease (COVID-19) pandemic led to a catastrophic burden on the healthcare system and increased expenditures for the supporting medical infrastructure. It also had dramatic socioeconomic consequences. The purpose of this study is to identify the empirical patterns of healthcare expenditures' influence on sustainable economic growth in the pandemic and pre-pandemic periods. Fulfilment of the research task involves the implementation of two empirical blocks: (1) development of a Sustainable Economic Growth Index based on public health, environmental, social, and economic indicators using principal component analysis, ranking, Fishburne approach, and additive convolution; (2) modelling the impact of different kinds of healthcare expenditures (current, capital, general government, private, out-of-pocket) on the index using panel data regression modelling (random-effects GLS regression). Regression results in the pre-pandemic period show that the growth of capital, government, and private healthcare expenditures positively influence sustainable economic growth. In 2020-2021, healthcare expenditures did not statistically significantly influence sustainable economic growth. Consequently, more stable conditions allowed capital healthcare expenditures to boost economic growth, while an excessive healthcare expenditure burden damaged economic stability during the COVID-19 pandemic. In the pre-pandemic period, public and private healthcare expenditures ensured sustainable economic growth; out-of-pocket healthcare expenditures dominantly contributed to the pandemic period.

Climate-friendly, health-promoting, and culturally acceptable diets for German adult omnivores, pescatarians, vegetarians, and vegans - a linear programming approach

OBJECTIVES

A frequently suggested approach to reduce greenhouse gas emissions (GHGEs) caused by food production is to reduce the intake of animal products, which can create nutritional deficiencies. This study aimed to identify culturally acceptable nutritional solutions for German adults that are both climate friendly and health promoting.

METHODS

Linear programming was applied to optimize the food supply for omnivores, pescatarians, vegetarians, and vegans considering nutritional adequacy, health promotion, GHGEs, affordability, and cultural acceptability by approaching German national food consumption.

RESULTS

Implementing dietary reference values and omitting meat (products) reduced the GHGEs by ≤52%. The vegan diet was alone in staying below the Intergovernmental Panel on Climate Change (IPCC) threshold of 1.6 kg carbon dioxide equivalents per person per day. The optimized omnivorous diet constrained to meet this goal maintained ≥50% of each baseline food and, on average, deviated from baseline by 36% for women and 64% for men. Butter, milk, meat products, and cheese were reduced by half for both sexes, whereas bread, bakery goods, milk, and meat were reduced mainly for men. The intake of vegetables, cereals, pulses, mushrooms, and fish increased by between 63% and 260% for the omnivores, compared with baseline. Besides the vegan dietary pattern, all optimized diets cost less than the baseline diet.

CONCLUSIONS

A linear programming approach for optimizing the German habitual diet to be healthy, affordable, and meet the IPCC GHGE threshold was possible for several dietary patterns and appears to be a feasible way forward toward including climate goals into food-based dietary guidelines.

Alternative dietary protein sources to support healthy and active skeletal muscle aging

To mitigate the age-related decline in skeletal muscle quantity and quality, and the associated negative health outcomes, it has been proposed that dietary protein recommendations for older adults should be increased alongside an active lifestyle and/or structured exercise training. Concomitantly, there are growing environmental concerns associated with the production of animal-based dietary protein sources. The question therefore arises as to where this dietary protein required for meeting the protein demands of the rapidly aging global population should (or could) be obtained. Various non-animal-derived protein sources possess favorable sustainability credentials, though much less is known (compared with animal-derived proteins) about their ability to influence muscle anabolism. It is also likely that the anabolic potential of various alternative protein sources varies markedly, with the majority of options remaining to be investigated. The purpose of this review was to thoroughly assess the current evidence base for the utility of alternative protein sources (plants, fungi, insects, algae, and lab-grown "meat") to support muscle anabolism in (active) older adults. The solid existing data portfolio requires considerable expansion to encompass the strategic evaluation of the various types of dietary protein sources. Such data will ultimately be necessary to support desirable alterations and refinements in nutritional guidelines to support healthy and active aging, while concomitantly securing a sustainable food future.

Carbon dioxide (CO2) emissions and adherence to Mediterranean diet in an adult population: the Mediterranean diet index as a pollution level index

BACKGROUND

Research related to sustainable diets is is highly relevant to provide better understanding of the impact of dietary intake on the health and the environment.

AIM

To assess the association between the adherence to an energy-restricted Mediterranean diet and the amount of CO₂ emitted in an older adult population.

DESIGN AND POPULATION

Using a cross-sectional design, the association between the adherence to an energy-reduced Mediterranean Diet (erMedDiet) score and dietary CO₂ emissions in 6646 participants was assessed.

METHODS

Food intake and adherence to the erMedDiet was assessed using validated food frequency questionnaire and 17-item Mediterranean questionnaire. Sociodemographic characteristics were documented. Environmental impact was calculated through greenhouse gas emissions estimations, specifically CO₂ emissions of each participant diet per day, using a European database. Participants were distributed in quartiles according to their estimated CO₂ emissions expressed in kg/day: Q1 (≤2.01 kg CO₂), Q2 (2.02-2.34 kg CO₂), Q3 (2.35-2.79 kg CO₂) and Q4 (≥2.80 kg CO₂).

RESULTS

More men than women induced higher dietary levels of CO₂ emissions. Participants reporting higher consumption of vegetables, fruits, legumes, nuts, whole cereals, preferring white meat, and having less consumption of red meat were mostly emitting less kg of CO₂ through diet. Participants with higher adherence to the Mediterranean Diet showed lower odds for dietary CO₂ emissions: Q2 (OR 0.87; 95%CI: 0.76-1.00), Q3 (OR 0.69; 95%CI: 0.69-0.79) and Q4 (OR 0.48; 95%CI: 0.42-0.55) vs Q1 (reference).

CONCLUSIONS

The Mediterranean diet can be environmentally protective since the higher the adherence to the Mediterranean diet, the lower total dietary CO₂ emissions. Mediterranean Diet index may be used as a pollution level index.

Sustainable choices: The relationship between adherence to the dietary guidelines and food waste behaviors in Italian families

Introduction

Food loss and waste are urgent problems to address. Recent estimates highlighted that the highest quantities of waste are generated at the household level and for this reason, the interest in this sector has increased over years.

Methods

To investigate if there is a connection between consumers' behaviors aiming at reducing food waste and consumers' choices in adopting healthy eating habits, a survey among a sample (n = 2,869) representative of the Italian population was carried out with the use of validated questionnaires.

Results

Results demonstrated that the higher the adherence to the Italian dietary guidelines indicator (AIDGI) the higher the score measuring household food waste behaviors (HFWB). In particular, the highest AIDGI corresponds to a preponderance of respondents that was more able to plan the shopping and the use of food (38.9%, p < 0.001), to better evaluate the quantities to cook (40.4%, p < 0.001), to avoid impulsive buying (35.2%, p < 0.01), to have a high knowledge of the food stored (38.4%, p < 0.001), to reuse leftovers (35.4%, p < 0.001), to assess food safety (34.7%, p < 0.001), to plan accurately (34.9%, p < 0.01), to know how to prolong the shelf life of a product (34%, p < 0.05), and to cook creatively (32%, p < 0.01). In addition to that, half of the respondents with the lowest AIDGI score did not receive any education regarding food waste (51.1%, p < 0.001). HFWB indicators globally resulted in scores ranging from 40 to 80% revealing the attention of Italians to food waste issues. Regarding eating habits, in half of the sample (50.4%) a consumption pattern with low adherence to nutritional recommendations was found, in particular among men (34.4%), younger age groups (40%), and people living in large families (42.3%).

Discussion

The overall results provided interesting information that could give input for planning nutrition education actions and identifying targets and topics to be addressed.

Pathways to sustainable land use and food systems in Canada

Meeting global sustainability targets under the United Nations Sustainable Development Goals and the Paris Agreement requires paying attention to major land-use sectors such as forestry and agriculture. These sectors play a large role in national emissions, biodiversity conservation, and human well-being. There are numerous possible pathways to sustainability in these sectors and potential synergies and trade-offs along those pathways. This paper reports on the use of a model for Canada's land use to 2050 to assess three different pathways (one based on current trends and two with differing levels of ambition for meeting sustainability targets). This was done as part of a large international consortium, Food, Agriculture, Biodiversity, Land and Energy (FABLE), which allows for incorporating international trade in meeting both national and global sustainability targets. The results show not only the importance of increasingly stringent policies in meeting the targets, but also the role that population and consumption (e.g., diets) play in meeting the targets. Both the medium and high ambition sustainability pathways can drastically reduce greenhouse gas emissions while protecting forestland.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11625-022-01213-z.

Healthy and Sustainable Diet Index: Development, Application and Evaluation Using Image-Based Food Records

There are limited methods to assess how dietary patterns adhere to a healthy and sustainable diet. The aim of this study was to develop a theoretically derived Healthy and Sustainable Diet Index (HSDI). The HSDI uses 12 components within five categories related to environmental sustainability: animal-based foods, seasonal fruits and vegetables, ultra-processed energy-dense nutrient-poor foods, packaged foods and food waste. A maximum of 90 points indicates the highest adherence. The HSDI was applied to 4-day mobile food records (mFRTM) from 247 adults (18−30 years). The mean HSDI score was 42.7 (SD 9.3). Participants who ate meat were less likely to eat vegetables (p < 0.001) and those who ate non-animal protein foods were more likely to eat more fruit (p < 0.001), vegetables (p < 0.05), and milk, yoghurt and cheese (p < 0.05). After adjusting for age, sex and body mass index, multivariable regression found the strongest predictor of the likelihood of being in the lowest total HSDI score tertile were people who only took a bit of notice [OR (95%CI) 5.276 (1.775, 15.681) p < 0.005] or did not pay much/any attention to the health aspects of their diet [OR (95%CI) 8.308 (2.572, 26.836) p < 0.0001]. HSDI provides a new reference standard to assess adherence to a healthy and sustainable diet.

Transitioning to sustainable healthy diets: A model-based and conceptual system thinking approach to optimized sustainable diet concepts in the United States

Food production and consumption are essential in human existence, yet they are implicated in the high occurrences of preventable chronic diseases and environmental degradation. Although healthy food may not necessarily be sustainable and vice versa, there is an opportunity to make our food both healthy and sustainable. Attempts have been made to conceptualize how sustainable healthy food may be produced and consumed; however, available data suggest a rise in the prevalence of health-related and negative environmental consequences of our food supply. Thus, the transition from conceptual frameworks to implementing these concepts has not always been effective. This paper explores the relative environmental and health risks associated with highly consumed food groups and develops a methodological workflow for evaluating the sustainability of diet concepts in the context of different health, socio-economic and environmental indicators. In addition, we apply the multi-criteria decision-making techniques (an integrated Analytic Hierarchy Process- Technique for order preference by similarity to ideal solution (AHP-TOPSIS) model) to examine the health and environmental impact of selected sustainable healthy diet concepts implemented in the United States. The principal findings indicate that adopting plant-based diet patterns would benefit the environment and the population's health. However, the up-scale, broad adoption and implementation of these concepts are hindered by critical bottlenecks. Hence we propose potential modification strategies through a conceptual system thinking approach to deliver optimized sustainable diet concepts to aid in the realization of the anticipated benefits of adoption/implementation.

Consensus-building around the conceptualisation and implementation of sustainable healthy diets: a foundation for policymakers

BACKGROUND

Healthy and sustainable diets need to be adopted to reduce the negative impact of food consumption on human and planetary health. Food systems account for a third of greenhouse gas emissions. "Dietary Patterns for Health and Sustainability" is a World Health Organization (WHO) project that aims to build consensus among international food, health, and sustainability experts and policymakers on how to conceptualise healthy and sustainable diets and on the actions and policies that could be implemented in the WHO European Region to promote these diets.

METHODS

A qualitative study among European food, health, and sustainability experts and policymakers to elicit their views on multiple dimensions of food sustainability and health was carried out using a three-phase process, including semi-structured interviews, a Nominal Group Technique, and focus groups during a participatory WHO workshop held in Copenhagen. Thematic analysis was used to analyse the three data sources.

RESULTS

The workshop resulted in a shared understanding of the interconnected components of sustainable healthy eating habits. As a result of this understanding, a variety of potential solutions were identified, including actions across different policy domains, tools, strategic guidelines, needs, and pathways for sustainable healthy diets. The pathways included the need for a multi-stakeholder approach, as well as the simultaneous execution of an aligned and coherent mix of policies at the local and national levels.

CONCLUSIONS

The prioritised actions should be aimed at helping government policymakers promote sustainable healthy diets and make decisions on improving dietary patterns for citizens' health and wellbeing in line with the United Nations Sustainable Development Goals in the European Region.

Development and preliminary validity of an Indonesian mobile application for a balanced and sustainable diet for obesity management

Background

Mobile applications such as personalized tracking tools and food choice aids may enhance weight loss programs. We developed and assessed client preferences for the content, user interface, graphics, and logic flow of a mobile application, and evaluated its validity for tracking compliance with weight control and making healthy and sustainable food choices.

Methods

Our four-stage study comprised formative research, application development, acceptance assessment, and validity. The formative research included literature reviews and six focus groups with 39 respondents aged 19–64 years at high risk for obesity. The development stage included programmer selection, defining application specifications, design, and user interface. Prototype acceptability was assessed with 53 respondents who graded 17 features of content, graphic design, and application flow (ranked as good, moderate, and poor). A feature was considered to have "good" acceptance if its mean response was higher than the mean of overall responses. The validity was assessed in 30 obese women using Bland–Altman plots to compare results from dietary intake assessment from the application to conventional paper-based methods.

Results

The application was named as EatsUp®. The focus group participants defined the key requirements of this app as being informative, easy, and exciting to use. The EatsUp® core features consisted of simple menu recommendations, health news, notifications, a food database, estimated portion sizes, and food pictures. The prototype had a "good" overall acceptance regarding content, graphics, and flow. Fourteen out of 17 parameters were graded as "good" from > 70% of respondents. There was no significant difference between the rated proportions for content, graphics, and app flow (Kolmogorov–Smirnov Z-test, p > .05). The agreement using the Bland–Altman plots between EatsUp® and the paper-based method of measuring food intake was good, with a mean difference of energy intake of only 2.63 ± 28.4 kcal/day (p > 0.05), well within the 95% confidence interval for agreement.

Conclusions

The EatsUp® mobile application had good acceptance for graphics and app flow. This application can support the monitoring of balanced and sustainable dietary practice by providing nutritional data, and is comparable with conventional dietary assessment tools, and performed well in tracking energy, macronutrient, and selected micronutrients intakes.

Trial registration

NCT03469869. The registration date was March 19, 2018.

Sustainability Dimensions of the Mediterranean Diet: A Systematic Review of the Indicators Used and Its Results

The concern about sustainability is growing and the Mediterranean diet has been extensively identified as a promising model, with benefits for human and environmental health. This systematic review aims to identify and describe the indicators that have been used to evaluate the sustainability of the Mediterranean diet and the results from their application. A methodology using PRISMA guidelines was followed, and searches were performed in Web of Science, PubMed, Scopus, and GreenFile. A total of 32 studies assessing the sustainability of the Mediterranean diet were identified. Twenty-five of these studies quantified the environmental impact, 7 studies evaluated the nutritional quality, and 12 studies assessed the daily cost of this dietary pattern. A total of 33 distinct indicators were identified, of which 10 were used to assess the environmental dimension (mainly, carbon, water, and ecological footprint), 8 were used to assess the nutritional dimension (mainly Health score and Nutrient Rich Food Index), 1 was used to assess the economic dimension (dietary cost), and 8 used combined indicators. The remaining 6 indicators for the assessment of sociocultural dimension were only identified in 1 study but were not measured. The Mediterranean diet had a lower environmental impact than Western diets and showed a carbon footprint between 0.9 and 6.88 kg CO2/d per capita, a water footprint between 600 and 5280 m3/d per capita, and an ecological footprint between 2.8 and 53.42 m2/d per capita. With regard to the nutritional dimension, the Mediterranean diet had a high nutritional quality and obtained 122 points on the Health score and ranged between 12.95 and 90.6 points on the Nutrient Rich Food Index. The cost of the Mediterranean diet is similar to other diets and varied between 3.33 and 14.42€/d per capita. These findings show that no uniformity in assessing the MDiet's sustainability exists.

Leveraging the Dynamics of Food Supply Chains towards Avenues of Sustainability

Increased globalization and the surging count of the population across the world indicate the need for more sustainable supply chains, especially those allied with the food industry. Nowadays, the demand for processed food items is increasing and establishing new markets globally. The sequence of activities starting from the farm and ending at the fork determines the sustainability within processed food supply chain (FSC) dynamics. Emphasizing sustainability-based performance systems in the processed FSC marks an effective and efficient utilization of resources, strengthening the dimension of economic, environmental, and societal benefits. The presented work aimed to review the avenues for adopting sustainability in the actions of Indian processed FSCs. For the same relation hierarchical models, clustering the various key enactors of sustainability in processed FSCs, every functional tier was developed. This relational, hierarchical framework was contemplated by implying the Pythagorean fuzzy set. The proposed methodology handled the mutual interrelation between the enactors and the uncertainty associated with human judgments, establishing the sequence of sustainability enactors. Outcomes of the presented study have implications in developing the framework, policy formulation, decisional attributes, facilitating field practitioners in streamlining, and embedding sustainability within the actions of processed FSCs.

Water-Food-Carbon Nexus Related to the Producer-Consumer Link: A Review

Clarifying the water-food-carbon nexus is key to promoting the harmonious development of human society and environmental resources. The sustainable development of agricultural production systems is being challenged by water scarcity and climate change. Crop growth and irrigation consume large amounts of water, and greenhouse gases are generated due to processes such as fertilizer application and enteric fermentation. These environmental impacts accompany the agricultural production process and are thus embedded in the entire life cycle of diverse food items; in turn, consumers' food choices indirectly impact water consumption and greenhouse gas emissions. Reducing agricultural water consumption and greenhouse gas emissions during food production have become crucial issues in mitigating the projected water, climate, and food crises. From the consumer's perspective, diets vary regionally due to different natural conditions for food production and varying socioeconomic and income levels. This review delves into the interactions between diet and its potential environmental impacts, including water consumption and greenhouse gas emissions, in order to support further development of the water-food-carbon nexus.

Climate-Changed Wheat: The Effect of Smaller Kernels on the Nutritional Value of Wheat

Through plant breeding and improved agronomy, the average wheat kernel size increased globally by about 40% from 1940 to 2000. Millers demand larger kernels because they contain more white flour (endosperm). Climate pressures are resulting in frequently reduced kernel size and routine rejection by the commodity system. If whole-wheat flour instead of white flour is the target, these smaller kernels have unrealized value. A total of 94% of Americans do not meet the recommended fiber intake, and inadequate fiber intake plays a role in the development of multiple chronic diseases. A total of 98% of the fiber in wheat is found in the bran. Bran content was measured in “big” (x¯ = 0.042 g/kernel) and “small” (x¯ = 0.023 g/kernel) kernels in nine varieties over locations and years. On average, small kernels contained 15.9% more bran than big kernels (n = 54, p < 0.001) and, thus, had higher mineral and fiber content. In the majority of cases, baking showed no difference in whole-wheat quality among flours within the same variety, regardless of kernel size, based on bread slice height and surface area. Wheat that was rejected by commercial mills as too small produced satisfactory bread. Favoring larger kernels and white flour production has unintended health consequences. Valuing smaller kernels and whole-wheat production provides an outlet for farmers dealing with increasing climate pressures and leads to an end-use product which can improve human health by increasing dietary fiber consumption.

Food-Level Analysis to Identify Dietary Choices With the Highest Nutritional Quality and Lowest Greenhouse Gas Emissions and Price

Introduction

Food systems are challenged to provide healthy, sustainable and affordable foods. From a consumer perspective, identifying healthy, sustainable and affordable choices based on individual food products rather than diets could promote better shopping choices.

Objective

To identify foods and drinks with the highest nutritional quality and lowest greenhouse gas emissions (GHGE) and price. We also assessed how a combination of these indicators (e.g., nutritional quality, GHGE and price) for food categories aligned with current United Kingdom dietary recommendations.

Materials and Methods

We performed a secondary analysis of the National Diet and Nutrition Survey (NDNS) nutrient databank year 11 (2018/2019). Spearman correlation coefficients were used to assess the strength of relationships between nutritional quality, environmental impact and/or prices per 100 kcal. In addition, we developed an optimized nutritional quality, GHGE and price score for each food or drink item based on the overall medians for each of these indicators.

Results

Median nutritional value was highest for fruit and vegetables, whilst median GHGE and price was lower for starchy carbohydrates, fats and items of which consumption should be limited. The relative proportions of foods considered the most nutritious and with a low GHGE and price in each of the food categories, on a per 100 kcal basis, were comparable to the proportions in the Eatwell Guide, except for the proportion of fruits and vegetables being smaller and the proportion of potatoes, bread, rice, pasta, and other starchy carbohydrates being larger in our analysis.

Conclusion

Public health efforts should consider the impact of dietary choices not only in terms of nutritional quality but also in terms of environmental and economic impact. Our food-based analysis shows a large variation in nutritional quality, GHGE and price within and across food categories, which provides consumers with opportunities for "food swaps" that are more nutritious and have lower GHGE and price.

Can a Greenhouse Gas Emissions Tax on Food also Be Healthy and Equitable? A Systemised Review and Modelling Study from Aotearoa New Zealand

Policies to mitigate climate change are essential. The objective of this paper was to estimate the impact of greenhouse gas (GHG) food taxes and assess whether such a tax could also have health benefits in Aotearoa NZ. We undertook a systemised review on GHG food taxes to inform four tax scenarios, including one combined with a subsidy. These scenarios were modelled to estimate lifetime impacts on quality-adjusted health years (QALY), health inequities by ethnicity, GHG emissions, health system costs and food costs to the individual. Twenty-eight modelling studies on food tax policies were identified. Taxes resulted in decreased consumption of the targeted foods (e.g., -15.4% in beef/ruminant consumption, N = 12 studies) and an average decrease of 8.3% in GHG emissions (N = 19 studies). The "GHG weighted tax on all foods" scenario had the largest health gains and costs savings (455,800 QALYs and NZD 8.8 billion), followed by the tax-fruit and vegetable subsidy scenario (410,400 QALYs and NZD 6.4 billion). All scenarios were associated with reduced GHG emissions and higher age standardised per capita QALYs for Māori. Applying taxes that target foods with high GHG emissions has the potential to be effective for reducing GHG emissions and to result in co-benefits for population health.

Identifying effective interventions to promote consumption of protein-rich foods from lower ecological footprint sources: A systematic literature review

Addressing overconsumption of protein-rich foods from high ecological footprint sources can have positive impacts on health such as reduction of non-communicable disease risk and protecting the natural environment. With the increased attention towards development of ecologically sustainable diets, this systematic review aimed to critically review literature on effectiveness of those interventions aiming to promote protein-rich foods from lower ecological footprint sources. Five electronic databases (Medline, Web of Science, Scopus, Embase and Global Health) were searched for articles published up to January 2021. Quantitative studies were eligible for inclusion if they reported on actual or intended consumption of protein-rich animal-derived and/or plant-based foods; purchase, or selection of meat/plant-based diet in real or virtual environments. We assessed 140 full-text articles for eligibility of which 51 were included in this review. The results were narratively synthesised. Included studies were categorised into individual level behaviour change interventions (n = 33) which included education, counselling and self-monitoring, and micro-environmental/structural behaviour change interventions (n = 18) which included menu manipulation, choice architecture and multicomponent approaches. Half of individual level interventions (52%) aimed to reduce red/processed meat intake among people with current/past chronic conditions which reduced meat intake in the short term. The majority of micro-environmental studies focused on increasing plant-based diet in dining facilities, leading to positive dietary changes. These findings point to a clear gap in the current evidence base for interventions that promote plant-based diet in the general population.

Advantages and limitations of the methodological approaches used to study dietary shifts towards improved nutrition and sustainability

Acting on diet is one of the changes required - in combination with actions on food production, transformation, and waste - to address the challenges of reducing the environmental impact of our food systems and eliminating all forms of malnutrition. The number of studies exploring how to move towards a more sustainable diet has exploded over the past decades, but there is a need to facilitate their understanding and use by policy makers and all other stakeholders possibly influencing diet sustainability. The aim of the present article is to propose a categorization of studies into 4 approaches, based on the type of methodology used to explore diet sustainability, and to highlight the principles, advantages, and limitations of each approach in order to help study users in their interpretation. The 4 approaches are: assessment of sustainability characteristics of hypothetical diets (approach 1) or existing diets (approach 2), identification of existing "positive deviants" (approach 3), and design of more sustainable diets with constrained optimization (approach 4). Specificities and key findings drawn from each approach are described, and challenges for future studies are discussed.

Influencing Factors for Sustainable Dietary Transformation—A Case Study of German Food Consumption

In a case study of Germany, we examine current food consumption along the three pillars of sustainability to evaluate external factors that influence consumers’ dietary decisions. We investigate to what extent diets meet nutritional requirements (social factor), the diets’ environmental impact (ecological factor), and the food prices’ influence on purchasing behavior (economic factor). For this, we compare two dietary recommendations (plant-based, omnivorous) with the status quo, and we examine different consumption styles (conventional, organic produce). Additionally, we evaluate 1446 prices of food items from three store types (organic store, supermarket, and discounter). With this, we are able to evaluate and compare 30 different food baskets along their health, environmental, and economic impact. Results show that purchasing decisions are only slightly influenced by health-related factors. Furthermore, few consumers align their diet with low environmental impact. In contrast, a large share of consumers opt for cheap foods, regardless of health and environmental consequences. We find that price is, arguably, the main factor in food choices from a sustainability standpoint. Action should be taken by policy makers to financially incentivize consumers in favor of healthy and environmentally friendly diets. Otherwise, the status quo further drives especially underprivileged consumers towards unhealthy and environmentally damaging consumption.

Variations in greenhouse gas emissions of individual diets: Associations between the greenhouse gas emissions and nutrient intake in the United Kingdom

BACKGROUND

Food production accounts for 30% of global greenhouse gas (GHG) emissions. Less environmentally sustainable diets are also often more processed, energy-dense and nutrient-poor. To date, the environmental impact of diets have mostly been based on a limited number of broad food groups.

OBJECTIVES

We link GHG emissions to over 3000 foods, assessing associations between individuals' GHG emissions, their nutrient requirements and their demographic characteristics. We also identify additional information required in dietary assessment to generate more accurate environmental impact data for individual-level diets.

METHODS

GHG emissions of individual foods, including process stages prior to retail, were added to the UK Composition Of Foods Integrated Dataset (COFID) composition tables and linked to automated online dietary assessment for 212 adults over three 24-hour periods. Variations in GHG emissions were explored by dietary pattern, demographic characteristics and World Health Organization Recommended Nutrient Intakes (RNIs).

RESULTS

GHG emissions estimates were linked to 98% (n = 3233) of food items. Meat explained 32% of diet-related GHG emissions; 15% from drinks; 14% from dairy; and 8% from cakes, biscuits and confectionery. Non-vegetarian diets had GHG emissions 59% (95% CI 18%, 115%) higher than vegetarian. Men had 41% (20%, 64%) higher GHG emissions than women. Individuals meeting RNIs for saturated fats, carbohydrates and sodium had lower GHG emissions compared to those exceeding the RNI.

DISCUSSION

Policies encouraging sustainable diets should focus on plant-based diets. Substituting tea, coffee and alcohol with more sustainable alternatives, whilst reducing less nutritious sweet snacks, presents further opportunities. Healthier diets had lower GHG emissions, demonstrating consistency between planetary and personal health. Further detail could be gained from incorporating brand, production methods, post-retail emissions, country of origin, and additional environmental impact indicators.

Development of the University Food Environment Assessment (Uni-Food) Tool and Process to Benchmark the Healthiness, Equity, and Environmental Sustainability of University Food Environments

Globally, there is increasing interest in monitoring actions to create healthy, equitable and environmentally sustainable food environments. Currently, there is a lack of detailed tools for monitoring and benchmarking university food environments. This study aimed to develop the University Food Environment Assessment (Uni-Food) tool and process to benchmark the healthiness, equity, and environmental sustainability of food environments in tertiary education settings, and pilot test its implementation in three Australian universities in 2021. The Uni-Food tool development was informed by a review of the literature and input from an expert advisory panel. It comprises three components: (1) university systems and governance, (2) campus facilities and environments, and (3) food retail outlets. The process for implementing the tool is designed for universities to self-assess the extent to which they have implemented recommended practice in 68 indicators, across 16 domains, weighted based on their relative importance. The pilot implementation of the tool identified moderate diversity in food environments across universities and highlighted several opportunities for improvements at each institution. The assessment process was found to be reliable, with assessors rating the tool as easy to use, requiring minimal resources. Broad application of the tool has the potential to increase accountability and guide best practice in tertiary education and other complex institutional settings.

The global and regional costs of healthy and sustainable dietary patterns: a modelling study

BACKGROUND

Adoption of healthy and sustainable diets could be essential for safe-guarding the Earth's natural resources and reducing diet-related mortality, but their adoption could be hampered if such diets proved to be more expensive and unaffordable for some populations. Therefore, we aimed to estimate the costs of healthy and sustainable diets around the world.

METHODS

In this modelling study, we used regionally comparable food prices from the International Comparison Program for 150 countries. We paired those prices with estimates of food demand for different dietary patterns that, in modelling studies, have been associated with reductions in premature mortality and environmental resource demand, including nutritionally balanced flexitarian, pescatarian, vegetarian, and vegan diets. We used estimates of food waste and projections of food demand and prices to specify food system and socioeconomic change scenarios up to 2050. In the full cost accounting, we estimated diet-related health-care costs by pairing a comparative risk assessment of dietary risks with cost-of-illness estimates, and we estimated climate change costs by pairing the diet scenarios with greenhouse gas emission footprints and estimates of the social cost of carbon.

FINDINGS

Compared with the cost of current diets, the healthy and sustainable dietary patterns were, depending on the pattern, up to 22-34% lower in cost in upper-middle-income to high-income countries on average (when considering statistical means), but at least 18-29% more expensive in lower-middle-income to low-income countries. Reductions in food waste, a favourable socioeconomic development scenario, and a fuller cost accounting that included the diet-related costs of climate change and health care in the cost of diets increased the affordability of the dietary patterns in our future projections. When these measures were combined, the healthy and sustainable dietary patterns were up to 25-29% lower in cost in low-income to lower-middle-income countries, and up to 37% lower in cost on average, for the year 2050. Variants of vegetarian and vegan dietary patterns were generally most affordable, and pescatarian diets were least affordable.

INTERPRETATION

In high-income and upper-middle-income countries, dietary change interventions that incentivise adoption of healthy and sustainable diets can help consumers in those countries reduce costs while, at the same time, contribute to fulfilling national climate change commitments and reduce public health spending. In low-income and lower-middle-income countries, healthy and sustainable diets are substantially less costly than western diets and can also be cost-competitive in the medium-to-long term, subject to beneficial socioeconomic development and reductions in food waste. A fuller accounting of the costs of diets would make healthy and sustainable diets the least costly option in most countries in the future.

FUNDING

Global Panel on Agriculture and Food Systems for Nutrition and Wellcome Trust.

What Influences the Sustainable Food Consumption Behaviours of University Students? A Systematic Review

Objectives: Global environmental challenges demand sustainable behaviours and policies to protect human and planetary health. We aimed to summarize the evidence about the factors related to Sustainable Food Consumption (SFC) behaviours of university students, and to propose an operational categorization of SFC behaviours.

Methods: Seven databases were searched for observational studies evaluating Sustainable Food Consumption (SFC) among university students and that reported at least one behavioural outcome measure. Qualitative synthesis was conducted, and PRISMA guidelines for reporting were followed.

Results: Out of 4,479 unique references identified, 40 studies were selected. All studies examined personal factors, while 11 out of 40 also measured social or situational factors. Except for food waste, females had higher levels of SFC behaviours, but situational factors moderated this association. Knowledge and attitudes showed mixed results. Overall, sustainable food consumers reported healthier lifestyles.

Conclusions: Healthy lifestyle of sustainable food consumers suggests possible synergies between human health and sustainability in terms of motivations for food choice. Moderation effects of social and situational factors on personal factors reveal opportunities to design and examine the effects of choice architecture interventions.

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.

Diet quality and all-cause mortality among US adults, estimated from National Health and Nutrition Examination Survey (NHANES), 2003-2008

OBJECTIVE

We assessed the ability of the Prime Diet Quality Score (PDQS) to predict mortality in the US population and compared its predictiveness with that of the Healthy Eating Index-2015 (HEI-2015).

DESIGN

PDQS and HEI-2015 scores were derived using two 24-h recalls and converted to quintiles. Mortality data were obtained from the 2015 Public-Use Linked Mortality File. Associations between diet quality and all-cause mortality were evaluated using multivariable Cox proportional hazards models, and predictive performance of the two metrics was compared using a Wald test of equality of coefficients with both scores in a single model. Finally, we evaluated associations between individual metric components and mortality.

SETTING

A prospective analysis of the US National Health and Nutrition Examination Survey (NHANES) data.

PARTICIPANTS

Five-thousand five hundred and twenty-five participants from three survey cycles (2003-2008) in the NHANES aged 40 years and over.

RESULTS

Over the 51 248 person-years of follow-up (mean: 9·2 years), 767 deaths were recorded. In multivariable models, hazard ratios between the highest and lowest quintiles of diet quality scores were 0·70 (95 % CI 0·51, 0·96, Ptrend = 0·03) for the PDQS and 0·77 (95 % CI 0·57, 1·03, Ptrend = 0·20) for the HEI-2015. The PDQS and HEI-2015 were similarly good predictors of total mortality (Pdifference = 0·88).

CONCLUSION

Among US adults, better diet quality measured by the PDQS was associated with reduced risk of all-cause mortality. Given that the PDQS is simpler to calculate than the HEI-2015, it should be evaluated further for use as a diet quality metric globally.

Eat Well to Fight Obesity… and Save Water: The Water Footprint of Different Diets and Caloric Intake and Its Relationship With Adiposity

Water scarcity and excess adiposity are two of the main problems worldwide and in Mexico, which is the most obese country in the world and suffers from water scarcity. Food production represents 90% of a person's water footprint (WF), and healthy diets can lead to less WF than do unhealthy diets related to obesity. We calculated the WF of the diet and caloric intake of adults in Mexico and analyzed its relationship with adiposity. Also, the risk of water expenditure due to adiposity and adherence to dietary recommendations regarding WF of international healthy diets were examined. A Food Consumption Frequency Questionnaire (FCFQ) was applied to 395 adults. Body mass index (BMI), associated with adiposity indicators, was used as a reference for grouping a sample into adiposity levels. The WF was calculated according to the WF Assessment Method, considering correction factors and accounting for water involved in cooking and food washing. Our results showed that the Mexican diet spends 6,056 liters per person per day (L p-1d-1) and is 55% higher than international healthy diets WF. Consumption of beef, milk, fruits, chicken, and fatty cereals represented 56% of total WF. Strong relations appeared between hypercaloric diets and high WF. Diets of people with excess adiposity generated statistically higher WF with extra expenses of 729 L p-1d-1 compared with the normal adiposity population. Following nutritional recommendations offers a protective factor in water care, whereas not adhering to these represents a risk up to 93 times greater of water expenditure regarding international healthy diets. Therefore, both for the general population and to regulate obesity, adequate diets can help mitigate the problem of water scarcity.

Sustainability Transitions in University Food Service—A Living Lab Approach of Locavore Meal Planning and Procurement

Due to its purchasing power, the public food service sector is viewed as a potential transformative driver towards sustainable food systems. Organic meal planning and regional procurement may be a vital implementation strategy towards Planetary Health Diets in the communal catering arena. Capable of unleashing desirable synergies within local foodsheds, this transition pathway can potentially benefit all stages of the value chain, while also positively influencing consumer dietary behavior. Transformation, however, poses complex challenges to caterers, as it demands a shift in mindset regarding the philosophy, organization, and management of cafeteria systems as well as the need for affordable and aggregated supplies of source-identified local organic foods. This action research case study engaged the public caterer of a German University, undergraduate students, and additional stakeholders in a Living Lab to develop a weekly farm-to-table cafeteria menu, including its actual preparation, based on a conceptual sustainability standard. Hence, through an iterative process, involving two feedback cycles, an ambitious set of nutritional and procurement criteria were devised, inspired by the external input from exemplary practitioners in the field of green cuisine and procurement. The resulting meal plan was then subjected to an evaluation vis-á-vis its compliance with (1) dietary recommendations, (2) seasonality, (3) organic certification, (4) a defined foodshed boundary, (5) budget neutrality, and (6) life cycle assessment.

Introducing Plant-Based Mediterranean Diet as a Lifestyle Medicine Approach in Latin America: Opportunities Within the Chilean Context

Latin America is experiencing a significant epidemiological and nutritional transition, with a trend toward higher incidence of food-related chronic diseases. In this context, Lifestyle Medicine (LM) is a growing field focused on assisting individuals in adopting healthy behaviors for the prevention and treatment of these chronic diseases, including, among other pillars, a great emphasis on healthy eating. There is also a growing interest worldwide in environmental sustainability of dietary patterns, with increasing concern about their effects on planetary health. In this context, whole-food, plant-based diets -such as the Mediterranean diet (MD)- have emerged as a solution for both healthier eating and lowering environmental impact. Yet in order to be effective at these goals and achieve a high adherence to any nutritional prescription, the sociocultural reality of the community or population where we aim to practice must also be taken into account. In this review, we specifically highlight the plant-based MD as a LM-contextualized dietary pattern that is adaptable, applicable, and sustainable within the Chilean context and has the potential to address the current trend of chronic diseases in our country.