The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review

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.

Puppy power: How neophobia, attitude towards sustainability, and animal empathy affect the demand for insect-based pet food

Despite growing commercial interest in novel foods, there are few studies that analyse consumer willingness to purchase them as pet food. This study aimed to test whether consumers are willing to accept the use of foods with insect-based ingredients, which are found to be poorly accepted for human consumption, to feed their pets. In our case study, we analysed the willingness of 400 Italian dog and/or cat caregivers to pay for pet foods containing insect proteins, as measured by the Multiple Price List methodology. We also explored the role of food neophobia, attention to environmental sustainability, and empathy toward one's pet. The results of the study pointed out that the usual determinants of acceptance in the consumption of novel foods, such as food neophobia and attention to environmental sustainability, play an important role even when the purchase is for the household pet, and that empathy as an expression of the pet caregiver's personal relationship with their pet becomes an additional factor. Insect-based pet foods proved to be attractive for purchase only when consumers are well informed about the product's properties in terms of sustainability and healthiness for their pets.

Health-environment efficiency of diets shows nonlinear trends over 1990-2011

Understanding the impacts of diets on health and the environment, as well as their association with socio-economic development, is key to operationalize and monitor food systems shifts. Here we propose a health-environment efficiency indicator defined as a ratio of health benefits and four key food-related environmental impacts (greenhouse gas emissions, scarcity-weighted water withdrawal, acidifying and eutrophying emissions) to assess how diets have performed in supporting healthy lives in relation to environmental pollution and resource consumption across 195 countries from 1990 to 2011. We find that the health-environment efficiency of each environmental input follows a nonlinear path along the Socio-Demographic Index gradient representing different development levels. Health-environment efficiency first increases thanks to the elimination of child and maternal malnutrition through greater food supply, then decreases driven by additional environmental impacts from a shift to animal products, and finally shows a slow growth in some developed countries again as they shift towards healthier diets.

Sustainable diets among youth: Validity and reliability of a questionnaire assessing knowledge, attitudes, practices, and willingness to change

BACKGROUND

In light of the global commitment to promoting sustainable dietary choices and the pivotal role of young adults in the adoption of these choices, it is paramount to understand their perspectives of healthy and sustainable diets. The present study aimed to investigate the validity and reliability of a questionnaire examining the knowledge, attitudes, practices, and willingness to change regarding sustainable diets among young adults in the United Arab Emirates (UAE).

METHODS

Male and female students attending University of Sharjah, UAE (n = 436), completed an online questionnaire consisting of four sections: knowledge, attitudes, practices, and willingness to change with regard to sustainable diets. Of the participants, 106 completed the questionnaire a second time, 1 month later. Factor analysis (FA) (both exploratory and confirmatory), Cronbach-α, interitem correlations, and intra class correlation (ICC) coefficients were used in the data analysis.

RESULTS

Exploratory FA revealed four factors corresponding to the components of the questionnaire. Results of the confirmatory FA indicated a good fit: the χ2 df ratio was < 5 (2.3), root mean squared error of approximation was < 0.08 (0.048) and the comparative fit index was above 0.9 (0.901). Cronbach α and interitem correlations were: knowledge: 0.57 and 0.21; attitude: 0.70 and 0.28; practices: 0.76 and 0.39; willingness to change: 0.69 and 0.27. The ICC coefficients, assessing the reliability of the questionnaire, ranged between 0.48 and 0.92 for the various items.

CONCLUSIONS

The developed questionnaire is a valid and reliable tool that could be used to identify the gaps and opportunities for the development of evidence-based interventions aiming to enhance the uptake of sustainable diets among young adults.

Algae Ingestion Increases Resting and Exercised Myofibrillar Protein Synthesis Rates to a Similar Extent as Mycoprotein in Young Adults

BACKGROUND

Spirulina [SPIR] (cyanobacterium) and chlorella [CHLO] (microalgae) are foods rich in protein and essential amino acids; however, their capacity to stimulate myofibrillar protein synthesis (MyoPS) in humans remains unknown.

OBJECTIVES

We assessed the impact of ingesting SPIR and CHLO compared with an established high-quality nonanimal-derived dietary protein source (fungal-derived mycoprotein [MYCO]) on plasma amino acid concentrations, as well as resting and postexercise MyoPS rates in young adults.

METHODS

Thirty-six healthy young adults (age: 22 ± 3 y; BMI: 23 ± 3 kg·m-2; male [m]/female [f], 18/18) participated in a randomized, double-blind, parallel-group trial. Participants received a primed, continuous infusion of L-[ring-2H5]-phenylalanine and completed a bout of unilateral-resistance leg exercise before ingesting a drink containing 25 g protein from MYCO (n = 12; m/f, 6/6), SPIR (n = 12; m/f, 6/6), or CHLO (n = 12; m/f, 6/6). Blood and bilateral muscle samples were collected at baseline and during a 4-h postprandial and postexercise period to assess the plasma amino acid concentrations and MyoPS rates in rested and exercised tissue.

RESULTS

Protein ingestion increased the plasma total and essential amino acid concentrations (time effects; all P < 0.001), but most rapidly and with higher peak responses following the ingestion of SPIR compared with MYCO and CHLO (P < 0.05), and MYCO compared with CHLO (P < 0.05). Protein ingestion increased MyoPS rates (time effect; P < 0.001) in both rested (MYCO, from 0.041 ± 0.032 to 0.060 ± 0.015%·h-1; SPIR, from 0.042 ± 0.030 to 0.066 ± 0.022%·h-1; and CHLO, from 0.037 ± 0.007 to 0.055 ± 0.019%·h-1, respectively) and exercised tissue (MYCO, from 0.046 ± 0.014 to 0.092 ± 0.024%·h-1; SPIR, from 0.038 ± 0.011 to 0.086 ± 0.028%·h-1; and CHLO, from 0.048 ± 0.019 to 0.090 ± 0.024%·h-1, respectively), with no differences between groups (interaction effect; P > 0.05), but with higher rates in exercised compared with rested muscle (time × exercise effect; P < 0.001).

CONCLUSIONS

The ingestion of a single bolus of algae-derived SPIR and CHLO increases resting and postexercise MyoPS rates to a comparable extent as MYCO, despite divergent postprandial plasma amino acid responses.

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.

What is the climate footprint of therapeutic diets for people with chronic kidney disease? Results from an Australian analysis

BACKGROUND

Immediate action is needed to stabilise the climate. Dietitians require knowledge of how the therapeutic diets they prescribe may contribute to climate change. No previous research has quantified the climate footprint of therapeutic diets. This study sought to quantify and compare the climate footprint of two types of therapeutic diets for people with chronic kidney disease (CKD) with two reference diets.

METHODS

A usual diet for an individual with CKD and a novel plant-based diet for CKD were compared with the current Australian diet and the Australian-adapted EAT Lancet Planetary Health Diet (PHD). The climate footprint of these diets was measured using the Global Warming Potential (GWP*) metric for a reference 71-year-old male.

RESULTS

No diets analysed were climate neutral, and therefore, all contribute to climate change. The novel plant-based diet for CKD (1.20 kg carbon dioxide equivalents [CO2 e] per day) produced 35% less CO2 e than the usual renal diet for an individual with CKD (1.83 kg CO2 e per day) and 50% less than the current Australian diet (2.38 kg CO2 e per day). The Australian-adapted EAT Lancet PHD (1.04 kg CO2 e per day) produced the least amount of CO2 e and 56% less than the current Australian diet. The largest contributors to the climate footprint of all four diets were foods from the meats and alternatives, dairy and alternatives and discretionary food groups.

CONCLUSIONS

Dietetic advice to reduce the climate footprint of therapeutic diets for CKD should focus on discretionary foods and some animal-based products. Future research is needed on other therapeutic diets.

Meat versus meat alternatives: which is better for the environment and health? A nutritional and environmental analysis of animal-based products compared with their plant-based alternatives

BACKGROUND

Poor diets lead to negative health outcomes, including increased risk of noncommunicable diseases. Food systems, most notably agriculture, contribute to greenhouse gas emissions (GHGE) that lead to climate change. Meat consumption plays a role in both health and environmental burden. Consumption of meat alternatives may reduce these harms. The aim was to compare meat products and their plant-based alternatives on nutritional parameters, GHGE and price to examine if it is feasible and beneficial for policymakers and health professionals to recommend meat alternatives.

METHODS

Data on nutritional information and cost for 99 selected products were collected from five UK supermarkets. Estimates for GHGEs for 97 of these products were found through secondary articles. Median values for nutritional value, GHGE (kgCO2 e) and price per 100 g were calculated to allow comparisons between meat products and their alternatives. Mann-Whitney U tests were used to look for significant differences for each nutrient, emissions and price.

RESULTS

Meat alternatives contained significantly more fibre and sugar and were significantly higher in price compared to the equivalent meat products. Meat alternatives had a significantly lower number of calories, saturated fat, protein and kgCO2 e than meat products. There was no significant difference in the amount of salt between meat and meat alternatives.

CONCLUSIONS

Overall, this paper found that meat alternatives are likely to be better for health according to most parameters, while also being more environmentally friendly, with lower GHGEs. However, the higher price of these products may be a barrier to switching to meat alternatives for the poorest in society.

Sustainable healthy diet modeling for a plant-based dietary transitioning in the United States

The potential environmental and nutritional benefits of plant-based dietary shifts require thorough investigation to outline suitable routes to achieve these benefits. Whereas dietary consumption is usually in composite forms, sustainable healthy diet assessments have not adequately addressed composite diets. In this study, we build on available data in the Food4HealthyLife calculator to develop 3 dietary concepts (M) containing 24 model composite diet scenarios (S) assessed for their environmental and nutritional performances. The Health Nutritional Index (HENI) and Food Compass scoring systems were used for nutritional quality profiling and estimates of environmental impact were derived from previously reported midpoint impact values for foods listed in the What We Eat in America database. The diets were ranked using the Kruskal‒Wallis nonparametric test, and a dual-scale data chart was employed for a trade-off analysis to identify the optimal composite diet scenario. The results showcased a distinct variation in ranks for each scenario on the environment and nutrition scales, describing an inherent nonlinear relationship between environmental and nutritional performances. However, trade-off analysis revealed a diet with 10% legumes, 0.11% red meat, 0.28% processed meat and 2.81% white meat could reduce global warming by 54.72% while yielding a diet quality of 74.13 on the Food Compass Scoring system. These observations provide an interesting forecast of the benefits of transitioning to an optimal plant- and animal-based dieting pattern, which advances global nutritional needs and environmental stewardship among consumers.

An Overview of Ingredients Used for Plant-Based Meat Analogue Production and Their Influence on Structural and Textural Properties of the Final Product

Plant-based meat analogues are food products made from vegetarian or vegan ingredients that are intended to mimic taste, texture and appearance of meat. They are becoming increasingly popular as people look for more sustainable and healthy protein sources. Furthermore, plant-based foods are marketed as foods with a low carbon footprint and represent a contribution of the consumers and the food industry to a cleaner and a climate-change-free Earth. Production processes of plant-based meat analogues often include technologies such as 3D printing, extrusion or shear cell where the ingredients have to be carefully picked because of their influence on structural and textural properties of the final product, and, in consequence, consumer perception and acceptance of the plant-based product. This review paper gives an extensive overview of meat analogue components, which affect the texture and the structure of the final product, discusses the complex interaction of those ingredients and reflects on numerous studies that have been performed in that area, but also emphasizes the need for future research and optimization of the mixture used in plant-based meat analogue production, as well as for optimization of the production process.

The Gap in Sustainable Food Services in Public Institutions: The Perceptions of Young Consumers from Public Universities in the Madrid Region (Spain)

The agri-food system needs to transition into a more balanced system that takes into account economic, social, and environmental factors. Young people are a key demographic group to consider as they are open to new trends of consumption, including sustainable buying practices. Public universities can play a significant role in promoting sustainable and healthy eating habits among students. In this paper, we focus on the perceptions of young people regarding sustainable food in the Madrid Region. We conducted a survey using a questionnaire-based approach among 1940 students in 2022. The results highlight that young consumers are highly concerned about food sustainability. They perceive sustainability as local and non-processed foods. However, this perception varies among young consumers, and we identified five different consumer profiles. Principal component analysis and cluster analysis provide insights into potential actions that universities can take to promote sustainable and healthy eating habits among students.

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.

Environmental pressures and pesticide exposure associated with an increase in the share of plant-based foods in the diet

Diets rich in plant-based foods are encouraged for human health and to preserve resources and the environment but the nutritional quality and safety of such diets is debated. This study aimed to model nutritionally adequate diets with increasing plant food content and to characterise the derived diets using a multicriteria approach including, nutrients intake, environmental pressures and exposure to pesticides. Using data of the NutriNet-Santé cohort (N = 29,413), we implemented stepwise optimization models to identified maximum plant-food content under nutritional constraints. Environmental indicators at the production level were derived from the DIALECTE database, and exposure to pesticide residues from plant food consumption was estimated using a contamination database. Plant-based foods contributed to 64.3% (SD = 10.6%) of energy intake in observed diets and may reach up to 95% in modelled diets without jeopardizing nutritional status. Compared to the observed situation, an increase in plant-based foods in the diets led to increases in soy-based products (+ 480%), dried fruits (+ 370%), legumes (+ 317%), whole grains (+ 251%), oils (+ 144%) and vegetables (+ 93%). Animal products decreased progressively until total eviction, except for beef (- 98%). Dietary quality (estimated using the Diet Quality Index Based on the Probability of Adequate Nutrient Intake) was improved (up to 17%) as well as GHGe (up to - 65%), energy demand (up to - 48%), and land occupation (- 56%) for production. Exposures to pesticides from plant-based foods were increased by 100% conventional production and to a much lesser extent by 100% organic production. This study shows that shifting to nutritionally-adequate plant-based diets requires an in-depth rearrangement of food groups' consumption but allows a drastic reduction environmental impact. Increase exposure to pesticide residues and related risks can be mitigated by consuming foods produced with low pesticide input.

Simple dietary substitutions can reduce carbon footprints and improve dietary quality across diverse segments of the US population

Changing what foods we eat could reduce environmental harms and improve human health, but sweeping dietary change is challenging. We used dietary intake data from a nationally representative sample of 7,753 US children and adults to identify simple, actionable dietary substitutions from higher- to lower-carbon foods (for example, substituting chicken for beef in mixed dishes such as burritos, but making no other changes to the diet). We simulated the potential impact of these substitutions on dietary carbon emissions and dietary quality. If all consumers who ate the high-carbon foods instead consumed a lower-carbon substitute, the total dietary carbon footprint in the United States would be reduced by more than 35%. Moreover, if adopted, these substitutions would improve consumers' overall dietary quality by 4-10%, with benefits projected for all age, gender, and racial and ethnic groups. These results suggest that a 'small changes' approach could be a valuable starting point for addressing diet's impact on climate and health.

Aligning Environmental Sustainability, Health Outcomes, and Affordability in Diet Quality: A Systematic Review

Improving diet quality while simultaneously maintaining planetary health is of critical interest globally. Despite the shared motivation, advancement remains slow, and the research community continues to operate in silos, focusing on certain pairings (diet-climate), or with a discipline-specific lens of a sustainable diet, rather than examining their totality. This review aimed to summarize the literature on adherence to a priori defined dietary patterns in consideration of diet quality, metabolic risk factors for noncommunicable diseases (NCDs), environmental impacts, and affordability. A methodology using PRISMA guidelines was followed, and searches were performed in 7 databases as of October 2022. The Appraisal tool for Cross-Sectional Studies (AXIS) and the National Institutes of Health (NIH) quality assessment tool for observational cohort studies were employed for quality appraisal. The evidence was narratively synthesized according to the characteristics of the diet quality metrics. The review includes 24 studies published between 2017-2023. Thirteen distinct diet quality scores were identified, with those measuring adherence to national dietary guidelines the most reported. Thirteen distinct environmental impact indicators were identified, with greenhouse gas emissions (n=23) reported most. All studies reported on body mass index, and 7 studies assessed the cost of adherence. Our results are consistent with previous findings that healthier diets can reduce environmental impacts; however, incongruities between population and planetary health can occur. Hence, the "sustainability" of dietary patterns is dependent on the choice of indicators selected. Further, healthy, lower impact diets can increase financial cost, but may also provide a protective role against the risk of obesity. Given the Global Syndemic, strategies to reduce obesity prevalence should emphasize the win-win opportunities for population and planetary health through dietary change. Research should identify diets that address multiple environmental concerns to curtail burdens potentially transferring, and harmonize this with sociocultural and equity dimensions. This review was registered at PROSPERO as CRD42021238055.

The nature of protein intake as a discriminating factor of diet sustainability: a multi-criteria approach

Animal production is responsible for 56-58% of the GHG emissions and limiting meat consumption would strongly contribute to reducing human health risks in Western countries. This study aimed to investigate the nature of protein intake as a discriminating factor for diets' sustainability. Using data from 29,210 French adults involved in the NutriNet-Santé cohort, we identified clusters according to 23 protein sources. A multicriteria (environmental, economic, nutritional and health) sustainability analysis was then conducted on the identified clusters. The economic analysis focused on both food and protein expenditure structures, using a budget coefficient approach. Relative values of clusters compared to the whole sample were calculated. We identified five clusters: milk-based, meat-based, fast food-based, healthy-fish-based, and healthy-plant-based. We found that the healthy-plant-based and healthy-fish-based clusters were the most sustainable, conciliating the compromise between human health (0.25 and 0.53 respectively for the Health Risk Score) and the protection of the environment (- 62% and - 19% respectively for the pReCiPe indicator). Conversely, the highest environmental impacts (+ 33% for the pReCiPe indicator) and the highest health risk (0.95 for the HRS) were observed for the meat-based cluster, which was associated with the lowest nutritional scores (- 61% for the PNNS-GS2 score). The economic analysis showed that the healthy-plant-based cluster was the one with the highest food budget coefficient (+ 46%), followed by the healthy-fish-based cluster (+ 8%), partly explained by a strong share of organic food in the diet. However, the meat-based cluster spent more of their food budget on their protein intake (+ 13%), while the healthy-plant-based cluster exhibited the lowest expenditure for this intake (- 41%). Our results demonstrate that the nature of protein intake is a discriminating factor in diet sustainability. Also, reducing animal protein consumption would generate co-benefits beyond environmental impacts, by being favorable for health, while reducing the monetary cost associated with protein intake.

The effect of an app-based dietary intervention on diet-related greenhouse gas emissions - results from a randomized controlled trial

BACKGROUND

Dietary change towards a diet low in greenhouse gas emissions (GHGEs) can reduce climate impact and improve individual-level health. However, there is a lack of understanding if diet interventions can achieve low-GHGE diets.

METHODS

A randomized controlled trial was conducted to assess the effects of an app-based intervention. The intervention was designed to improve dietary intake of people with Type 2 diabetes, and was delivered via an app over 12 weeks, with each week covering one diet-related topic. Dietary intake was assessed at baseline and 3-month follow up by a 95-item food frequency questionnaire and linked to GHGE values. A total of n = 93 participants (n = 46 and n = 47 for the intervention and control group, respectively) were included in the analysis. Changes to GHGEs within and between the groups were analysed with inferential statistics.

RESULTS

The majority (60%) of participants were male, with a mean age of 63.2 years and body mass index of 30 kg/m2. At baseline, diet-related GHGEs were 4.8 and 4.9 kg CO2-eq/day in the intervention and control group, respectively. At 3-month follow up the corresponding GHGEs were 4.7 and 4.9 kg CO2-eq/day. We found no statistically significant changes to diet-related GHGEs within or between groups, or within food categories, from baseline to 3-month follow up.

CONCLUSION

No evidence was found for the effectiveness of the app-based intervention to generate changes to diet-related GHGEs in a population of people with Type 2 diabetes. However, future interventions that target reducing meat consumption specifically may have the potential to result in a reduction of individual-level diet-related GHGEs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03784612. Registered 24 December 2018. www.

CLINICALTRIALS

gov/ct2/show/NCT03784612 .

What is on plates for school meals: focusing on animal- vs. plant-based protein foods

BACKGROUND/OBJECTIVES

This study aimed to analyze the potential of school meals in South Korea as a sustainable tool to reduce carbon emissions by focusing on animal- vs. plant-based protein foods.

MATERIALS/METHODS

By using a stratified proportional allocation method, 536 out of the 11,082 schools nationwide were selected including 21 kindergartens, 287 elementary-, 120 middle- and 108 high schools. A total of 2,680 meals served for 5 consecutive days (June 21-25, 2021) were collected. We analyzed the average serving amounts of protein foods (animal- vs. plant-based) per meal and then, calculated the estimated average amounts of carbon emission equivalents per meal by applying the conversion coefficients. The t-test and analysis of variance were used for statistical analyses (α = 0.05).

RESULTS

The average serving amount of animal-based protein foods per meal was 12.5 g, which was approximately 3 times higher than that of plant-based ones (3.8 g) (P < 0.001); the Meat-group had the highest average amount of 17.0 g, followed by Egg-group (9.6 g), Fish-group (7.6 g), and Beans-and-Nuts-group (3.8 g) (P < 0.05). Specifically, pork (25.1 g) was ranked first, followed by poultry (19.6 g), processed meat products (18.0 g). The estimated average amount of carbon emission equivalents of animal-based protein foods per meal was 80.1 g CO2e, which was approximately 31 times higher than that of plant-based ones (2.6 g CO2e) (P < 0.001); the Meat-group had the highest average amount of 120.3 g CO2e, followed by Fish-group (44.5 g CO2e), Egg-group (25.9 g CO2e), and Beans-and-Nuts-group (2.6 g CO2e) (P < 0.05). Specifically, processed meat products (270.8 g CO2e) were ranked first, followed by pork (91.7 g CO2e), and processed fish products (86.6 g CO2e).

CONCLUSIONS

The results implied that school meals with plant-based alternatives could be a sustainable tool to improve carbon footprint.

Occupational therapy's contributions to combating climate change and lifestyle diseases

BACKGROUND

The interdependence between human occupations, lifestyle diseases and climate change provides an opportunity to address them simultaneously. Occupational therapists' training in lifestyle modification and knowledge about the impact of the physical environment on daily occupations puts them in a unique position to contribute to global efforts of combating climate change and lifestyle diseases through the promotion of sustainable occupations.

AIM

To illustrate how occupational therapists can contribute to global efforts of combating climate change and lifestyle diseases by framing climate change from a personal and public health perspective.

METHOD

In this discussion paper we argue that occupational therapists can use education and lifestyle modification to support individuals in the prevention and management of lifestyle diseases and that they can help design and advocate for environments that promote sustainable occupations.

RESULT

This discussion paper highlights the contributions that occupational therapists can make to how we understand and address climate change and lifestyle diseases.

CONCLUSIONS AND SIGNIFICANCE

We argue that by framing the climate change discourse from a health perspective, occupational therapists can contribute to global efforts of combating climate change and lifestyle diseases by supporting individuals to engage in sustainable occupations and communities to facilitate this engagement.

An ecological network approach for detecting and validating influential organisms for rice growth

How to achieve sustainable food production while reducing environmental impacts is a major concern in agricultural science, and advanced breeding techniques are promising for achieving such goals. However, rice is usually grown under field conditions and influenced by surrounding ecological community members. How ecological communities influence the rice performance in the field has been underexplored despite the potential of ecological communities to establish an environment-friendly agricultural system. In the present study, we demonstrate an ecological-network-based approach to detect potentially influential, previously overlooked organisms for rice (Oryza sativa). First, we established small experimental rice plots, and measured rice growth and monitored ecological community dynamics intensively and extensively using quantitative environmental DNA metabarcoding in 2017 in Japan. We detected more than 1000 species (including microbes and macrobes such as insects) in the rice plots, and nonlinear time series analysis detected 52 potentially influential organisms with lower-level taxonomic information. The results of the time series analysis were validated under field conditions in 2019 by field manipulation experiments. In 2019, we focused on two species, Globisporangium nunn and Chironomus kiiensis, whose abundance was manipulated in artificial rice plots. The responses of rice, namely, the growth rate and gene expression patterns, were measured before and after the manipulation. We confirmed that, especially in the G. nunn-added treatment, rice growth rate and gene expression pattern were changed. In the present study, we demonstrated that intensive monitoring of an agricultural system and the application of nonlinear time series analysis were helpful to identify influential organisms under field conditions. Although the effects of the manipulations were relatively small, the research framework presented here has future potential to harness the ecological complexity and utilize it in agriculture. Our proof-of-concept study would be an important basis for the further development of field-basis system management.

Sustainable Isolation of Bioactive Compounds and Proteins from Plant-Based Food (and Byproducts)

Plant-based food produces significantly less greenhouse gases, and due to its wealth of bioactive components and/or plant-based protein, it becomes an alternative in a sustainable food system. However, the processing and production of products from plant sources creates byproducts, which can be waste or a source of useful substances that can be reused. The waste produced during the production and processing of food is essentially nutrient- and energy-rich, and it is recognized as an excellent source of secondary raw materials that could be repurposed in the process of manufacturing and preparing food, or as feed for livestock. This review offers an overview of the sources and techniques of the sustainable isolation of bioactive substances and proteins from various sources that might represent waste in the preparation or production of food of plant origin. The aim is to uncover novel approaches to use waste and byproducts from the process of making food to provide this waste food an additional benefit, not forgetting the expectations of the end user, the consumer. For the successful isolation of bioactive ingredients and proteins from food of plant origin, it is crucial to develop more eco-friendly and efficient extraction techniques with a low CO2 footprint while considering the economic aspects.

Improving school lunch menus with multi-objective optimisation: nutrition, cost, consumption and environmental impacts

OBJECTIVE

To support school foods programmes by evaluating the relationship between nutritional quality, cost, student consumption and the environmental impacts of menus.

DESIGN

Using linear programming and data from previously served menu items, the relationships between the nutritional quality, cost, student consumption and the environmental impacts of lunch menus were investigated. Optimised lunch menus with the maximum potential student consumption and nutritional quality and lowest costs and environmental impacts were developed and compared with previously served menus (baseline).

SETTING

Boston Public Schools (BPS), Boston Massachusetts, USA.

PARTICIPANTS

Menu items served on the 2018-2019 BPS lunch menu (n 142).

RESULTS

Using single-objective models, trade-offs were observed between most interests, but the use of multi-objective models minimised these trade-offs. Compared with the current weekly menus offered, multi-objective models increased potential caloric intake by up to 27 % and Healthy Eating Index scores by up to 19 % and reduced costs and environmental impacts by up to 13 % and 71 %, respectively. Improvements were made by reducing the frequency of beef and cheese entrées and increasing the frequency of fish and legume entrées on weekly menus.

CONCLUSIONS

This work can be extrapolated to monthly menus to provide further direction for school districts, and the methods can be employed with different recipes and constraints. Future research should test the implementation of optimised menus in schools and consider the broader implications of implementation.

A Comprehensive Analysis of the Nutritional Composition of Plant-Based Drinks and Yogurt Alternatives in Europe

Concerns for human and planetary health have led to a shift towards healthier plant-based diets. Plant-based dairy alternatives (PBDA) have experienced exponential market growth due to their lower environmental impact compared to dairy products. However, questions have arisen regarding their suitability as dairy substitutes and their role in food-based dietary guidelines (FBDG). Our study aimed to analyse the nutritional profiles of leading PBDA across Europe and compare them with their dairy counterparts. We examined the nutritional profiles of 309 unflavoured PBDA representing the European market leaders, including 249 plant-based drinks (PBD) and 52 plant-based alternatives to yogurt (PBAY). PBD and PBAY, excluding coconut varieties, were low in saturated fat (<1 g per serving). Seventy percent of PBDA were unsweetened, and most had sugar levels comparable to dairy. Except for soya varieties, PBDA protein levels were lower than dairy. Organic PBDA lacked micronutrients due to legal restrictions on fortification. Among non-organic PBDA, 76% were fortified with calcium, 66% with vitamin D, and 60% with vitamin B12. Less than half were fortified with vitamin B2, and a few with iodine (11%) and vitamin A (6%). PBAY were less frequently fortified compared to PBD. PBDA displayed a favourable macronutrient profile despite lower protein levels, which would be compensated for by other protein-dense foods in a usual mixed diet. Enhancing fortification consistency with dairy-associated micronutrients would address concerns regarding PBDA's integration into FBDG. Our analysis supports the inclusion of fortified PBDA in environmentally sustainable FBDG for healthy populations.

Bioactive compounds for human and planetary health

Bioactive compounds found in edible plants and foods are vital for human and planetary health, yet their significance remains underappreciated. These natural bioactives, as part of whole diets, ingredients, or supplements, can modulate multiple aspects of human health and wellness. Recent advancements in omic sciences and computational biology, combined with the development of Precision Nutrition, have contributed to the convergence of nutrition and medicine, as well as more efficient and affordable healthcare solutions that harness the power of food for prevention and therapy. Innovation in this field is crucial to feed a growing global population sustainably and healthily. This requires significant changes in our food system, spanning agriculture, production, distribution and consumption. As we are facing pressing planetary health challenges, investing in bioactive-based solutions is an opportunity to protect biodiversity and the health of our soils, waters, and the atmosphere, while also creating value for consumers, patients, communities, and stakeholders. Such research and innovation targets include alternative proteins, such as cellular agriculture and plant-derived protein; natural extracts that improve shelf-life as natural preservatives; upcycling of agricultural by-products to reduce food waste; and the development of natural alternatives to synthetic fertilizers and pesticides. Translational research and innovation in the field of natural bioactives are currently being developed at two levels, using a systems-oriented approach. First, at the biological level, the interplay between these compounds and the human host and microbiome is being elucidated through omics research, big data and artificial intelligence, to accelerate both discovery and validation. Second, at the ecosystem level, efforts are focused on producing diverse nutrient-rich, flavorful, and resilient, yet high-yield agricultural crops, and educating consumers to make informed choices that benefit both their health and the planet. Adopting a system-oriented perspective helps: unravel the intricate and dynamic relationships between bioactives, nutrition, and sustainability outcomes, harnessing the power of nature to promote human health and wellbeing; foster sustainable agriculture and protect the ecosystem. Interdisciplinary collaboration in this field is needed for a new era of research and development of practical food-based solutions for some of the most pressing challenges humanity and our planet are facing today.

Sustainable choices of plant-based ('super') foods: examining the consumption patterns of German consumers on avocados

This paper aims to better understand consumer awareness of the environmental impact of plant-based ('super'-) foods, using avocados as an example. Since all food production impacts the environment, both meat-based and plant-based, there is scope for more sustainable food choices. Avocados have positive health properties while being considered critically for the potential negative environmental impact of their production. This study examines the avocado consumption behaviour of German consumers and the extent to which knowledge and dietary patterns are related to this. Data from 373 respondents from Germany were collected through an online consumer survey. Bivariate comparisons for avocado consumption and logistic regression analyses were performed to explore avocado consumption behaviour. The frequency of avocado consumption among respondents was moderate, averaging once per month. Avocado consumption was related to a flexitarian diet, older age and higher income, and urban dwellers. Knowledge of the environmental impacts of avocado cultivation had no influence. Respondents' self-assessed knowledge about avocados was low. To help consumers in making conscious, sustainable choices for plant-based foods, it is necessary to provide accessible and comparable information on the environmental impact of food products. However, further life cycle assessments on avocado production are clearly needed in order to produce valid information material. A flexitarian diet with reduced consumption of animal foods is an important prerequisite for environmental sustainability. Drawing attention to environmentally friendly plant-based food choices for flexitarian consumers could further encourage them to become food innovators for a healthy planet by reducing climate impact, land use, and energy and water consumption.

The use of environmental scenarios to project future health effects: a scoping review

Environmental risks are a substantial factor in the current burden of disease, and their role is likely to increase in the future. Model-based scenario analysis is used extensively in environmental sciences to explore the potential effects of human activities on the environment. In this Review, we examine the literature on scenarios modelling environmental effects on health to identify the most relevant findings, common methods used, and important research gaps. Health outcomes and measures related to climate change (n=106) and air pollution (n=30) were most frequently studied. Studies examining future disease burden due to changes or policies related to dietary risks were much less common (n=10). Only a few studies assessed more than two environmental risks (n=3), even though risks can accumulate and interact with each other. Studies predominantly covered high-income countries and Asia. Sociodemographic, vulnerability, and health-system changes were rarely accounted for; thus, assessing the full effect of future environmental changes in an integrative way is not yet possible. We recommend that future models incorporate a broader set of determinants of health to more adequately capture their effect, as well as the effect of mitigation and adaptation efforts.

Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts

Modelled dietary scenarios often fail to reflect true dietary practice and do not account for variation in the environmental burden of food due to sourcing and production methods. Here we link dietary data from a sample of 55,504 vegans, vegetarians, fish-eaters and meat-eaters with food-level data on greenhouse gas emissions, land use, water use, eutrophication risk and potential biodiversity loss from a review of 570 life-cycle assessments covering more than 38,000 farms in 119 countries. Our results include the variation in food production and sourcing that is observed in the review of life-cycle assessments. All environmental indicators showed a positive association with amounts of animal-based food consumed. Dietary impacts of vegans were 25.1% (95% uncertainty interval, 15.1-37.0%) of high meat-eaters (≥100 g total meat consumed per day) for greenhouse gas emissions, 25.1% (7.1-44.5%) for land use, 46.4% (21.0-81.0%) for water use, 27.0% (19.4-40.4%) for eutrophication and 34.3% (12.0-65.3%) for biodiversity. At least 30% differences were found between low and high meat-eaters for most indicators. Despite substantial variation due to where and how food is produced, the relationship between environmental impact and animal-based food consumption is clear and should prompt the reduction of the latter.

Predicting the Adoption of a Sustainable Diet in Adults: A Cross-Sectional Study in Italy

Shifting food choices towards sustainability entails the analysis of dietary behavior determinants. This study aimed to explain and predict the intention to follow a sustainable diet and its adoption in a representative sample of adults (n = 838) in Italy. An online survey based on the theory of planned behavior (TPB) was developed. The adoption of a sustainable diet was measured as self-perceived behavior, adherence to the Mediterranean diet (MD), and food consumption frequencies. Psychometric analysis and correlations between attitude, subjective norms, and perceived behavioral control (PBC) with both intention and behavior assessments were evaluated. Structural equation models were used to test whether and to what extent attitude, subjective norms, and PBC explained intention and behavior. Significant associations were found between TPB constructs and the behavior measures underlining the main role of intention and PBC in affecting behavior. The applied TPB models explained behavioral intention at most (78%). The results suggested promising interventions in narrowing the attitude-behavior gap to encourage specific adult population groups in Italy to adopt virtuous food consumption habits. Beside the implementation of price mechanism strategies, educational initiatives to increase awareness about food and diet sustainability issues and the reinforcement of the perceived control on food consumption at the individual level are recommended.

The Bahraini food based dietary guidelines: a holistic perspective to health and wellbeing

The impact of food consumption extends well beyond the physical aspect of health to affect the mind, the society, and the environment. The biopsycho-ecological (BSE) theory recognizes the interplay between these factors and emphasizes the need for a holistic perspective to dietary recommendations. This manuscript presents a situation analysis of food consumption and diet-related diseases in Bahrain and describes the themes of the Bahraini Food based dietary guidelines (FBDG) and their alignment with the BSE constructs. Available data revealed low fruit and vegetable intake and excessive consumption of processed meat and sugary drinks in the country. These dietary habits are accompanied by a high burden of non-communicable diseases and their risk factors, anemia, and vitamin D deficiency. The Bahraini FBDG consisted of 11 context-specific themes and key messages that addressed the four dimensions of health depicted by the BSE theory, as follows: diet, physical activity, and food safety (body), physical activity, mindful eating and mental health (mind); family relations and cultural heritage (society), and food waste and environmental footprints of dietary intake (environment). The Bahraini FBDG present a model of dietary guidelines that adopted a holistic perspective to address health as they promote the role of food and dietary habits in maintaining the health of the body and that of the mind, the society, and the environment.

Evaluation of the fermentation potential of lactic acid bacteria isolated from herbs, fruits and vegetables as starter cultures in nut-based milk alternatives

Fermentation of plant-based milk alternatives (PBMAs), including nut-based products, has the potential to generate new foods with improved sensorial properties. In this study, we screened 593 lactic acid bacteria (LAB) isolates from herbs, fruits and vegetables for their ability to acidify an almond-based milk alternative. The majority of the strongest acidifying plant-based isolates were identified as Lactococcus lactis, which were found to lower the pH of almond milk faster than dairy yoghurt cultures. Whole genome sequencing (WGS) of 18 plant-based Lc. lactis isolates revealed the presence of sucrose utilisation genes (sacR, sacA, sacB and sacK) in the strongly acidifying strains (n = 17), which were absent in one non-acidifying strain. To confirm the importance of Lc. lactis sucrose metabolism in efficient acidification of nut-based milk alternatives, we obtained spontaneous mutants defective in sucrose utilisation and confirmed their mutations by WGS. One mutant containing a sucrose-6-phosphate hydrolase gene (sacA) frameshift mutation was unable to efficiently acidify almond, cashew and macadamia nut milk alternatives. Plant-based Lc. lactis isolates were heterogeneous in their possession of the nisin gene operon near the sucrose gene cluster. The results of this work show that sucrose-utilising plant-based Lc. lactis have potential as starter cultures for nut-based milk alternatives.

Should Men Eat More Plants? A Systematic Review of the Literature on the Effect of Plant-Forward Diets on Men's Health

OBJECTIVE

To perform a systematic review of the literature on plant-based and plant-forward diets and the prevention/treatment of the following common men's health conditions: prostate cancer (PCa), erectile dysfunction (ED), and benign prostatic hyperplasia (BPH).

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses system criteria were utilized to search PubMed and Medline databases for the following search terms: "Diet (Mesh)" OR "Diet Therapy (Mesh)" AND "Prostatic Hyperplasia (Mesh)" OR "Prostatic Neoplasm (Mesh)" OR "Erectile Dysfunction (Mesh)." Articles in English published from 1989 to 2022 using human participants were analyzed, data summarized, and assessed for bias.

RESULTS

Studies reporting on plant-based or vegetable-forward diets (Mediterranean) as an intervention were included. Cohort and cross-sectional studies using food frequency questionnaires or diet classification indices to quantify plant-based food intake patterns were included in the study. Ultimately, 12 PCa articles, 4 BPH articles, 6 ED articles, and 2 articles related to both BPH and ED were reviewed. Overall, the literature suggests plant-forward diets confer a protective effect on the men's health conditions reviewed.

CONCLUSIONS

Evaluation of the literature on the impact of plant-forward diets on urologic conditions includes a heterogenous range of dietary patterns and study designs. The greatest amount of research has evaluated the application of plant-forward diets for PCa. While there is currently a lack of high-quality evidence for the use of plant-forward diets as prevention and/or treatment for PCa, ED, or BPH, reported outcomes suggest a consistent small beneficial impact alongside well-established benefits for common chronic conditions.

Low-carbon diets can reduce global ecological and health costs

Potential external cost savings associated with the reduction of animal-sourced foods remain poorly understood. Here we combine life cycle assessment principles and monetarization factors to estimate the monetary worth of damage to human health and ecosystems caused by the environmental impacts of food production. We find that, globally, approximately US$2 of production-related external costs were embedded in every dollar of food expenditure in 2018-corresponding to US$14.0 trillion of externalities. A dietary shift away from animal-sourced foods could greatly reduce these 'hidden' costs, saving up to US$7.3 trillion worth of production-related health burden and ecosystem degradation while curbing carbon emissions. By comparing the health effects of dietary change from the consumption versus the production of food, we also show that omitting the latter means underestimating the benefits of more plant-based diets. Our analysis reveals the substantial potential of dietary change, particularly in high and upper-middle-income countries, to deliver socio-economic benefits while mitigating climate change.

Insight into the Sustainability of the Mediterranean Diet: The Water Footprint of the Recommended Italian Diet

At present, as we face climate change and natural resource scarcity, one of the major challenges linking humans and the environment is to ensure sufficient, nutritious, safe, and affordable food for a rapidly growing world population. In a nutshell, "feed the world without destroying it". The water footprint (WF), i.e., the withdrawals of fresh water necessary to produce one kilogram of food product, is one of the key indicators of the environmental impact of diets. In this work, the WF of the food patterns suggested by the Italian Food Based Dietary Guidelines, considered a model of the Mediterranean Diet, was evaluated for the first time. The data reported here clearly demonstrate that the suggested Italian dietary patterns have a low WF, the reduction of which by replacing animal foods with plant foods is limited because the suggested consumption of meat is already low. Consumer choice in the consumption of specific products within a food group could further reduce the WF of the diet, underlining the need to provide correct information not only to consumers but also to farmers and producers to encourage them to make water-saving choices.

PlantACT! - how to tackle the climate crisis

Greenhouse gas (GHG) emissions have created a global climate crisis which requires immediate interventions to mitigate the negative effects on all aspects of life on this planet. As current agriculture and land use contributes up to 25% of total GHG emissions, plant scientists take center stage in finding possible solutions for a transition to sustainable agriculture and land use. In this article, the PlantACT! (Plants for climate ACTion!) initiative of plant scientists lays out a road map of how and in which areas plant scientists can contribute to finding immediate, mid-term, and long-term solutions, and what changes are necessary to implement these solutions at the personal, institutional, and funding levels.

Transitioning to sustainable dietary patterns: learnings from animal-based and plant-based dietary patterns in French Canadian adults

Introduction

Many dietary guidelines promote the substitution of animal proteins with plant-based proteins for health benefits but also to help transitioning toward more sustainable dietary patterns. The aim of this study was to examine the food and nutrient characteristics as well as the overall quality and costs of dietary patterns consistent with lower intakes of animal-based protein foods and with higher intakes of plant-based protein foods among French Canadian adults.

Methods

Dietary intake data, evaluated with 24 h recalls, from 1,147 French-speaking adults of the PRÉDicteurs Individuels, Sociaux et Environnementaux (PREDISE) study conducted between 2015 and 2017 in Québec were used. Usual dietary intakes and diet costs were estimated with the National Cancer Institute's multivariate method. Consumption of animal- and plant-based protein foods was classified into quarters (Q) and differences in food and nutrient intakes, Healthy Eating Food Index (HEFI)-2019 scores and diet costs across quarters were assessed using linear regression models adjusted for age and sex.

Results

Participants with lower intakes of animal-based protein foods (Q1 vs. Q4) had a higher HEFI-2019 total score (+4.0 pts, 95% CI, 0.9 to 7.1) and lower daily diet costs (-1.9 $CAD, 95% CI, -2.6 to -1.2). Participants with higher intakes of plant-based protein foods (Q4 vs. Q1) had a higher HEFI-2019 total score (+14.6 pts, 95% CI, 12.4 to 16.9) but no difference in daily diet costs (0.0$CAD, 95% CI, -0.7 to 0.7).

Discussion

In a perspective of diet sustainability, results from this study among French-speaking Canadian adults suggest that a shift toward a dietary pattern focused primarily on lower amounts of animal-based protein foods may be associated with a better diet quality at lower costs. On the other hand, transitioning to a dietary pattern focused primarily on higher amounts of plant-based protein foods may further improve the diet quality at no additional cost.

Measurement of diets that are healthy, environmentally sustainable, affordable, and equitable: A scoping review of metrics, findings, and research gaps

Introduction

Research on the impacts of dietary patterns on human and planetary health is a rapidly growing field. A wide range of metrics, datasets, and analytical techniques has been used to explore the role of dietary choices/constraints in driving greenhouse gas (GHG) emissions, environmental degradation, health and disease outcomes, and the affordability of food baskets. Many argue that each domain is important, but few have tackled all simultaneously in analyzing diet-outcome relationships.

Methods

This paper reviews studies published between January 2015 and December 2021 (inclusive) that examined dietary patterns in relation to at least two of the following four thematic pillars: (i) planetary health, including, climate change, environmental quality, and natural resource impacts, (ii) human health and disease, (iii) economic outcomes, including diet cost/affordability, and (iv) social outcomes, e.g., wages, working conditions, and culturally relevant diets. We systematically screened 2,425 publications by title and abstract and included data from 42 eligible publications in this review.

Results

Most dietary patterns used were statistically estimated or simulated rather than observed. A rising number of studies consider the cost/affordability of dietary scenarios in relation to optimized environmental and health outcomes. However, only six publications incorporate social sustainability outcomes, which represents an under-explored dimension of food system concerns.

Discussion

This review suggests a need for (i) transparency and clarity in datasets used and analytical methods; (ii) explicit integration of indicators and metrics linking social and economic issues to the commonly assessed diet-climate-planetary ecology relationships; (iii) inclusion of data and researchers from low- and middle-income countries; (iv) inclusion of processed food products to reflect the reality of consumer choices globally; and (v) attention to the implications of findings for policymakers. Better understanding is urgently needed on dietary impacts on all relevant human and planetary domains simultaneously.

Plant-based and vegetarian diets: an overview and definition of these dietary patterns

PURPOSE

This paper aims to present an overview of the definitions of "plant-based and "vegetarian diets" adopted by different organizations worldwide, proposing new standard definitions and discussing the notion of vegetarianism as a restrictive dietary pattern.

METHODS

An extensive literature review on the different definitions of vegetarian and plant-based diets was conducted. Definitions of different international vegetarian and vegan organizations were also taken into account. Objective definitions for vegetarian and plant-based diets, as well as for their subcategories, were proposed. Other aspects related to how vegetarian diets are viewed and defined were also discussed.

RESULTS

We proposed that a vegetarian diet should be defined as "a dietary pattern that excludes meat, meat-derived foods, and, to different extents, other animal products". This definition would include, among others, ovolactovegetarian and vegan diets. The proposed definition for a plant-based diet was "a dietary pattern in which foods of animal origin are totally or mostly excluded". Other types of diets, such as flexitarian and pescetarian diets, could be considered plant-based. A vegetarian diet should not be considered restrictive. Instead, terms such as alternative or non-conventional could be used to define it and to distinguish it from the conventional diet adopted by most of the Western population.

CONCLUSION

This paper was able to elaborate objective definitions of vegetarian and plant-based diets. Standardizing nomenclatures may reduce misinterpretation and confusion in this field of study.

Higher adherence to the EAT-Lancet reference diet is associated with higher nutrient adequacy in the NutriNet-Santé cohort : a cross-sectional study

BACKGROUND

In 2019, the EAT-Lancet Commission proposed a planetary and healthy reference diet; however, its nutritional quality has been rarely evaluated.

OBJECTIVE

Across different adherence levels to the EAT-Lancet reference diet, the following were our objectives:1) describe the food and nutritional intakes of the French population, 2) to evaluate the nutrient quality and, 3) investigate the consistency between the French national recommendations and the EAT-Lancet reference diet.

DESIGN

This cross-sectional study was conducted among participants of the NutriNet-Santé cohort and the sample was weighted on the characteristics of the general French population. Adherence to the EAT-Lancet reference diet was estimated using the EAT-Lancet Diet Index (ELD-I). Usual nutrient intakes were obtained using the variance reduction method. We used the estimated average requirements cut-point method to estimate the proportion of participants who meet their respective nutritional requirements. Furthermore, the adequacy of the French food-based dietary recommendations (Programme National Nutrition Santé [PNNS]) according to adherence to the EAT-Lancet reference diet was studied.

RESULTS

The weighted sample was composed of 98,465 participants. Except for bioavailable zinc and vitamin B12, we observed a decrease in the nutrient inadequacy prevalence when the adherence to the EAT-Lancet reference diet increased, particularly for vitamin B9 (Q1=37.8% vs. Q5=5.5%, p=<0.0001) and vitamin C (Q1=59.0% vs. Q5=10.8 %, p=<0.0001). However, inadequacy prevalence remained high in all ELD-I quintiles, particularly for fiber (95.9%), vitamin B1 (70.8%), iodine (48.4%), and magnesium (76.8%). Higher ELD-I score was associated with higher adherence for most components of the PNNS, except for food groups that are not specifically included in the EAT-Lancet reference diet and are typical of the French diet, including alcohol, processed meat, and salt.

CONCLUSION

In the French context, although issues with the intake of certain nutrients may occur, a diet that remains within the planetary limits as the EAT-Lancet reference diet allows a favorable nutritional quality.

TRIAL REGISTRATION NUMBER

NCT03335644.

Popular diets as selected by adults in the United States show wide variation in carbon footprints and diet quality

BACKGROUND

Carbon footprints of vegetarian, pescatarian, and other popular diets have been studied previously, but mostly as idealized versions modeled to meet dietary recommendations. Less is known about the footprints of popular diets as they are consumed by US adults, and thus the potential trade-offs with diet quality for free-living individuals.

OBJECTIVES

This study estimated the carbon footprint and diet quality of popular diets as selected by a nationally representative sample of US consumers, including the recently trending keto- and paleo-style diets.

METHODS

The 2005-2010 NHANES 24-h recall data were used to categorize individual adult diets (n = 16,412) into 6 types: vegan, vegetarian, pescatarian, paleo, keto, and all other diets, referred to here as omnivore diets. Average daily greenhouse gas emissions in kilograms of carbon dioxide equivalents per 1000 kcal (kg CO2-eq/1000 kcal) were calculated for each diet by matching our previously developed database to NHANES individual diet data. Diet quality was determined using the Healthy Eating Index (HEI) and the Alternate Healthy Eating Index. Survey-weighted ordinary least-squares regression was used to assess mean differences in diets.

RESULTS

The average carbon footprints of vegan (0.69 ± 0.05 kg CO2-eq/1000 kcal) and vegetarian (1.16 ± 0.02) diets were lower (P < 0.05) than those of the pescatarian (1.66 ± 0.04), omnivore (2.23 ± 0.01), paleo (2.62 ± 0.33), or keto (2.91 ± 0.27) diets. Mean HEI scores were highest for pescatarian diets (58.76 ± 0.79) and higher (P < 0.05) for vegetarian (51.89 ± 0.74) than for omnivore (48.92 ± 0.33) or keto (43.69 ± 1.61) diets.

CONCLUSIONS

Our results highlight the nuances when evaluating the nutritional quality of diets and their carbon footprints. On average, pescatarian diets may be the healthiest, but plant-based diets have lower carbon footprints than other popular diets, including keto- and paleo-style diets.

Relationship between adherence to the Mediterranean diet, sustainable and healthy eating behaviors, and awareness of reducing the ecological footprint

This study evaluated the relationship between adherence to the Mediterranean diet (MD), sustainable and healthy eating behaviors, and awareness of reducing the ecological footprint. It was conducted with 1333 adults (38.2% male, 61.8% female, mean age 24.2 ± 7.5 years). The questionnaire included socio-demographic characteristics, anthropometric measurements, the Awareness Scale for Reducing Ecological Footprint (ASREF), the Sustainable and Healthy Eating (SHE) Behaviors Scale, and Mediterranean Diet Adherence Scale (MEDAS). 40.2% of the participants adhered to the MD (≥7 scores). Obese individuals' total scores on MEDAS, SHE Behaviors Scale, and ASREF were the lowest (p < 0.05). In regression analysis, education duration, SHE Behaviors Scale total score, and BMI affected the ASREF score (p < 0.05). The education duration, SHE Behaviors Scale scores, and ASREF scores were higher in those in MD-adherence group (p < 0.05). In conclusion, adherence to the MD was associated with higher sustainable and healthy eating behaviors and higher awareness of ecological footprint reduction.

Strategies for reducing meat consumption within college and university settings: A systematic review and meta-analysis

Introduction

Despite the considerable public and planetary health benefits associated with reducing the amount of meat consumed in high-income countries, there is a limited empirical understanding of how these voluntary changes in food choice can be effectively facilitated across different settings. While prior reviews have given us broad insights into the varying capacities of behavior change strategies to promote meaningful reductions in meat consumption, none have compared how they perform relative to each other within a uniform dining context.

Methods

To address this gap in the literature, we synthesized the available research on university-implemented meat reduction interventions and examined the variations in the success rates and effect estimates associated with each of the three approaches identified in our systematic review.

Results

From our analyses of the 31 studies that met our criteria for inclusion (n = 31), we found that most were successful in reducing the amount of meat consumed within university settings. Moreover, independent of the number of individual strategies being used, multimodal interventions were found to be more reliable and effective in facilitating these changes in food choice than interventions targeting the choice architecture of the retail environment or conscious decision-making processes alone.

Discussion

In addition to demonstrating the overall value of behavior change initiatives in advancing more sustainable dining practices on college and university campuses, this study lends further insights into the merits and mechanics underlying strategically integrated approaches to dietary change. Further investigations exploring the persistence and generalizability of these effects and intervention design principles are needed.

Systematic review registration

https://doi.org/10.17605/OSF.IO/DXQ5V, identifier: 10.17605/OSF.IO/DXQ5V.

Carbon footprint, economic benefits and sustainable fishing: Lessons for the future from the Western Mediterranean

Ensuring an economically viable, sustainable and low CO₂ emission extractive fishery is critical in order to achieve the life below water UN sustainable development goals and the climate change commitments of Paris agreement. This challenge is even more relevant in the most overexploited region of the world: The Mediterranean Sea. Here, we use the socio-ecological system of the Spanish Mediterranean commercial fisheries (Northern Alboran Sea, Northern Spain and the Balearic Islands) to develop an integrative impact assessment, including detailed socio-economic, ecosystem indices of the trophic structure of extractive fishery and CO₂ emission analyses combining different gear, vessel size classes as well as a wide range estimation of carbon release from the seafloor by bottom trawling. Northern Alboran Sea preferentially requires reduction in purse seine fishery while in Northern Spain bottom trawling should be reduced first to reach sustainable exploitation. Fuel CO₂ footprint of purse seine and bottom trawling are among the lowest footprints of animal protein production, but considering sweeping released CO₂ from the seafloor the bottom trawling footprint becomes the animal protein production with the highest footprint. Moreover, the lowest bottom released CO₂ estimation overrides 2.7-10 times the CO₂ buried in the seafloor through the biological pump in trawled areas potentially turning the continental shelf from a CO₂ sink to a CO₂ source. Net profit per fuel derived CO₂ emission for all fleets is lower than 1€ kgCO₂^-1, being lowest for large bottom trawler (0.025 € kgCO₂^-1). Thus, urgent mitigation and adaptation measures are necessary to obtain sustainable fishery in terms of net profit, sustainable seafood extraction and CO₂ emission reduction. Our study provides scientific bases to develop these measures such as the restriction of harmful fishing gear in carbon rich river influenced areas, reduction of bottom contact of the fishing gear, favouring purse seine fishery and smaller bottom trawlers.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Assessing the interlinkage between biodiversity and diet through the Mediterranean diet case

The adoption of healthy and sustainable diets, and the transition to sustainable food systems is of principal importance in order to counteract the double burden of climate change and non-communicable diseases. The Mediterranean diet (MD) has been widely recognized as a biodiversity and healthy nutrition resource to support sustainable development and food security. This study explored biodiversity in terms of food plants species, subspecies, varieties and races, and also addressed food-plant diversity differences between the MD and western-type consumption patterns. It was funded by the EU BioValue Project, aiming to promote the integration of underutilized crops into the food value chains. Using a two-stage scheme, data were selected from MEDUSA and Euro+Med databases (including 449 species, 2,366 subspecies, varieties, and races). Furthermore, 12 countries from North Africa and Europe were classified in two groups according to their sub-regional attributes and their traditionally most prevalent dietary pattern (MD or western-type diets). Statistical analysis showed that the mean of the majorly cultivated food plants in the MD was significantly higher than its counterpart in the Western-diet. Furthermore, no statistical difference was detected in the averages of native food plants between the MD group and the Western diet group, implying that the higher diversity in food plants observed in the MD seems to be attributed to crop utilization rather than crop availability. Our findings indicated the interlinkage between biodiversity and prevailing dietary patterns, and further underlined that biodiversity could constitute a prerequisite for dietary diversity, and hence nutrition security. In addition, this study demonstrated that diets and nutrition should be approached in a broader way within the context of both agro-food and ecological systems.

The role of family medicine and primary health care and its impact on the climate crisis

No abstract available.

Consumers' attitudes towards alternatives to conventional meat products: Expectations about taste and satisfaction, and the role of disgust

The livestock sector has environmental, health, and animal welfare impacts. This UK-based, quantitative study aimed to elucidate consumers' valuation of alternatives to conventional meat products. In an online study, 151 meat eaters and 44 non-meat eaters were shown pictures of meat, dairy, and bakery products, including beef burger, cheese sandwich and blueberry muffin. Each product was evaluated with three different labels (e.g., 'conventional', 'plant-based' and 'cultured' for beef burger). Participants rated expected taste pleasantness, fullness, satisfaction, healthiness, disgust and willingness-to-pay for each product/label combination. The results obtained demonstrate that alternatives to conventional meat products overall are acceptable to both meat and non-meat eaters. Although meat eaters' expected plant-based meat alternatives to be less satisfying, due to lower expected taste pleasantness and fillingness (Cohen's d = 0.14 to 0.63), they perceived the plant-based alternatives to be more healthy (d ≥ 1.18). Cultured meat products were perceived by meat eaters to be equally or more healthy, but more disgusting (d ≥ 0.41), than conventional meat products. These results suggest there is an opportunity to promote (motivate) acceptance of alternatives to conventional meat products based on their perceived healthiness, to at least partly balance reduced expected taste pleasantness and other negative attributes (i.e., barriers).

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

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