Health effects of adopting low greenhouse gas emission diets in the UK

Plant-based diets and urological health

Plant-based diets have grown in popularity owing to multiple health and environmental benefits. Some evidence suggests that plant-based diets are associated with benefits for urological health. In genitourinary oncology, most research has focused on prostate cancer. Clinical trial results suggest a favourable influence of healthy lifestyle modifications including plant-based diets before and after prostate cancer treatment. Epidemiological evidence shows that a diet higher in plant-based and lower in animal-based food is associated with a lower risk of aggressive prostate cancer and better quality-of-life scores than a diet with less plant-based and more animal-based food. Studies on bladder and kidney cancer are scarce, but limited data suggest that vegetarian or plant-forward dietary patterns (increased consumption of fruits and vegetables and minimizing meat) are associated with a lower risk of development of these cancers than dietary patterns with fewer fruits and vegetables and more meat. With respect to benign urological conditions, epidemiological studies suggest that plant-based dietary patterns are associated with a lower risk of benign prostatic hyperplasia and urinary tract infections than non-plant-based dietary patterns. Compared with diets high in animal-based foods and low in plant-based foods, a substantial body of epidemiological evidence also suggests that increased consumption of healthy plant-based food is associated with a lower risk of erectile dysfunction. Plant-based dietary patterns that are high in fruits and vegetables with normal calcium intake, while limiting animal protein and salt, are associated with a lower risk of kidney stone development than dietary patterns that do not follow these parameters. Overall, increasing consumption of plant-based foods and reducing intake of animal-based foods has favourable associations with multiple urological conditions.

Moderate low-cost modifications in diet prevent a substantial number of deaths and mitigate environmental impacts in Brazil

PURPOSE

This study aimed to estimate the health, economic, and environmental impacts of moderate simulated interventions on dietary intake in Brazil.

METHODS

Data on food price and consumption were obtained from three nationwide surveys. Baseline dietary intake was estimated for 33,859 individuals aged 25 years and older. Counterfactual intakes were based on six hypothetical intervention scenarios, by changing the weekly frequency and serving size in low or high consumers of fruit and vegetables (FV), milk, whole grains, red and processed meats, and sugar-sweetened beverages. For each scenario, we estimated the attributable number of deaths and disability-adjusted life years (DALY), monetary cost, environmental impacts (14 midpoint indicators), and environmentally-mediated health impacts.

RESULTS

Compared with the baseline intake and cost, the most expensive intervention (+ 8.3%) was to increase FV intake (+ 125 g), resulting in a 1.2% reduction in all-cause mortality (16,307 deaths/year). The cheapest (- 9.9%) was to reduce red and processed meat intake (- 40 g), resulting in a 1.1% reduction in all-cause mortality (14,272 deaths/year). The combined intervention was, on average, 3.7% cheaper than the baseline cost, resulting in an increase in diet cost for 30% of the population (45-22% in the lower- and higher-income groups); all-cause mortality would be reduced by 3.8% (49,488 deaths/year). Interventions targeting red and processed meats would reduce emissions and resource use by 35-55%, in addition to reducing 2300 DALYs/year.

CONCLUSION

A meaningful number of deaths can be avoided and environmental impacts reduced through moderate and potentially affordable diet modifications.

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.

The Impact of Climate Change and Extreme Weather Conditions on Cardiovascular Health and Acute Cardiovascular Diseases

Climate change is widely recognized as one of the most significant challenges facing our planet and human civilization. Human activities such as the burning of fossil fuels, deforestation, and industrial processes release greenhouse gases into the atmosphere, leading to a warming of the Earth's climate. The relationship between climate change and cardiovascular (CV) health, mediated by air pollution and increased ambient temperatures, is complex and very heterogeneous. The main mechanisms underlying the pathogenesis of CV disease at extreme temperatures involve several regulatory pathways, including temperature-sympathetic reactivity, the cold-activated renin-angiotensin system, dehydration, extreme temperature-induced electrolyte imbalances, and heat stroke-induced systemic inflammatory responses. The interplay of these mechanisms may vary based on individual factors, environmental conditions, and an overall health background. The net outcome is a significant increase in CV mortality and a higher incidence of hypertension, type II diabetes mellitus, acute myocardial infarction (AMI), heart failure, and cardiac arrhythmias. Patients with pre-existing CV disorders may be more vulnerable to the effects of global warming and extreme temperatures. There is an urgent need for a comprehensive intervention that spans from the individual level to a systemic or global approach to effectively address this existential problem. Future programs aimed at reducing CV and environmental burdens should require cross-disciplinary collaboration involving physicians, researchers, public health workers, political scientists, legislators, and national leaders to mitigate the effects of climate change.

The Plant-based Prescription: How Dietary Change Can Improve Both Urological and Planetary Health

In this editorial, we discuss the relationship between meat consumption and many major urological conditions (eg, prostate cancer, kidney stones, urinary tract infections) and how dietary choices could simultaneously benefit genitourinary health and the environment, which in turn will have downstream impacts on public health.

Diabetes and climate change

It is widely accepted that climate change is the biggest threat to human health. The pandemic of diabetes is also a major threat to human health, especially in rapidly developing nations. Climate change and diabetes appear to have common global vectors, including increased urbanisation, increased use of transportation, and production and ingestion of ultra-processed foods. People with diabetes appear to be at higher risk of threats to health from climate change, including effects from extreme heat or extreme cold, and natural disasters. Solutions to climate change offer some benefits for the prevention of diabetes and diabetes-related complications. Moving towards lower carbon economies is likely to help reduce reliance on intensive agriculture, reduce physical inactivity, reduce air pollution and enhance quality of life. It may enable a reduction in the prevalence of diabetes and reduced morbidity from the condition.

Impact on mortality of pathways to net zero greenhouse gas emissions in England and Wales: a multisectoral modelling study

BACKGROUND

The UK is legally committed to reduce its greenhouse gas emissions to net zero by 2050. We aimed to understand the potential impact on population health of two pathways for achieving this target through the integrated effects of six actions in four sectors.

METHODS

In this multisectoral modelling study we assessed the impact on population health in England and Wales of six policy actions relating to electricity generation, transport, home energy, active travel, and diets relative to a baseline scenario in which climate actions, exposures, and behaviours were held constant at 2020 levels under two scenarios: the UK Climate Change Committee's Balanced Pathway of technological and behavioural measures; and its Widespread Engagement Pathway, which assumes more substantial changes to consumer behaviours. We quantified the impacts of each policy action on mortality using a life table comprising all exposures, behaviours, and health outcomes in a single model.

FINDINGS

Both scenarios are predicted to result in substantial reductions in mortality by 2050. The Widespread Engagement Pathway achieves a slightly greater reduction in outdoor fine particulate matter air pollution of 3·2 μg/m3 (33%) and, under assumptions of appropriate ventilation, a greater improvement in indoor air pollution (a decrease in indoor-generated fine particulate matter from 9·4 μg/m3 to 4·6 μg/m3) and winter temperatures (increasing from 17·8°C to 18·1°C), as well as appreciably greater changes in levels of active travel (27% increase in metabolic equivalent hours per week of walking and cycling) by 2050. Additionally, the greater reduction in red meat consumption (50% compared with 35% under the Balanced Pathway) by 2050 results in greater consumption of fruits (17-18 g/day), vegetables (22-23 g/day), and legumes (5-7 g/day). Combined actions under the Balanced Pathway result in more than 2 million cumulative life-years gained over 2021-50; the estimated gain under the Widespread Engagement Pathway is greater, corresponding to nearly 2·5 million life-years gained by 2050 and 13·7 million life-years gained by 2100.

INTERPRETATION

Reaching net zero greenhouse gas emissions is likely to lead to substantial benefits for public health in England and Wales, with the cumulative net benefits being correspondingly greater with a pathway that entails faster and more ambitious changes, especially in physical activity and diets.

FUNDING

National Institute for Health Research and the Wellcome Trust.

Climate change and the prevention of cardiovascular disease

Climate change is a worsening global crisis that will continue negatively impacting population health and well-being unless adaptation and mitigation interventions are rapidly implemented. Climate change-related cardiovascular disease is mediated by air pollution, increased ambient temperatures, vector-borne disease and mental health disorders. Climate change-related cardiovascular disease can be modulated by climate change adaptation; however, this process could result in significant health inequity because persons and populations of lower socioeconomic status have fewer adaptation options. Clear scientific evidence for climate change and its impact on human health have not yet resulted in the national and international impetus and policies necessary to slow climate change. As respected members of society who regularly communicate scientific evidence to patients, clinicians are well-positioned to advocate on the importance of addressing climate change. This narrative review summarizes the links between climate change and cardiovascular health, proposes actionable items clinicians and other healthcare providers can execute both in their personal life and as an advocate of climate policies, and encourages communication of the health impacts of climate change when counseling patients. Our aim is to inspire the reader to invest more time in communicating the most crucial public health issue of the 21st century to their patients.

Effectiveness of a teaching unit on the willingness to consume insect-based food - An intervention study with adolescents from Germany

This study investigated the effect of a four-lesson teaching unit titled "Entomophagy and Sustainability" on the willingness of adolescents in Germany to consume insect-based food (N = 114; M Age = 15.77 years; SD Age = 1.12 years; female = 58.8%). The main aim of the study was to test whether the teaching unit can induce long-term changes in selected nutritional-psychological factors (food disgust, food neophobia, food technology neophobia), attitudes, knowledge, and the willingness to consume insect-based food. For this purpose, a paper-pencil questionnaire was conducted immediately before (pre-test), immediately after (post-test), and approximately six weeks after (follow-up test) the teaching unit. Although significant changes in food disgust, food neophobia, food technology neophobia, attitudes, and knowledge were recorded, adolescents' willingness to consume insect-based food was not significantly increased. Attitudes were identified as the strongest predictor of adolescents' willingness to consume, while knowledge was not a significant predictor. Conclusions and recommendations that can be applied to other educational interventions are provided to increase the effectiveness of the teaching unit.

Do diets with higher carbon footprints increase the risk of mortality? A population-based simulation study using self-selected diets from the USA

OBJECTIVE

Are diets with a greater environmental impact less healthy? This is a key question for nutrition policy, but previous research does not provide a clear answer. To address this, our objective here was to test whether American diets with the highest carbon footprints predicted greater population-level mortality from diet-related chronic disease than those with the lowest.

DESIGN

Baseline dietary recall data were combined with a database of greenhouse gases emitted in the production of foods to estimate a carbon footprint for each diet. Diets were ranked on their carbon footprints and those in the highest and lowest quintiles were studied here. Preventable Risk Integrated Model (PRIME), an epidemiological modelling software, was used to assess CVD and cancer mortality for a simulated dietary change from the highest to the lowest impact diets. The diet-mortality relationships used by PRIME came from published meta-analyses of randomised controlled trials and prospective cohort studies.

SETTING

USA.

PARTICIPANTS

Baseline diets came from adults (n 12 865) in the nationally representative 2005-2010 National Health and Nutrition Examination Survey.

RESULTS

A simulated change at the population level from the highest to the lowest carbon footprint diets resulted in 23 739 (95 % CI 20 349, 27 065) fewer annual deaths from CVD and cancer. This represents a 1·83 % (95 % CI 1·57 %, 2·08 %) decrease in total deaths. About 95 % of deaths averted were from CVD.

CONCLUSIONS

Diets with the highest carbon footprints were associated with a greater risk of mortality than the lowest, suggesting that dietary guidance could incorporate sustainability information to reinforce health messaging.

Cost-effectiveness of a dietary and physical activity intervention in adolescents: a prototype modelling study based on the Engaging Adolescents in Changing Behaviour (EACH-B) programme

Objective

To assess costs, health outcomes and cost-effectiveness of interventions that aim to improve quality of diet and level of physical activity in adolescents.

Design

A Markov model was developed to assess four potential benefits of healthy behaviour for adolescents: better mental health (episodes of depression and generalised anxiety disorder), higher earnings and reduced incidence of type 2 diabetes and adverse pregnancy outcomes (in terms of preterm delivery). The model parameters were informed by published literature. The analysis took a societal perspective over a 20-year period. One-way and probabilistic sensitivity analyses for 10 000 simulations were conducted.

Participants

A hypothetical cohort of 100 adolescents with a mean age of 13 years.

Interventions

An exemplar school-based, multicomponent intervention that was developed by the Engaging Adolescents for Changing Behaviour programme, compared with usual schooling.

Outcome measure

Incremental cost-effectiveness ratio (ICER) as measured by cost per quality-adjusted life-year (QALY) gained.

Results

The exemplar dietary and physical activity intervention was associated with an incremental cost of £123 per adolescent and better health outcomes with a mean QALY gain of 0.0085 compared with usual schooling, resulting in an ICER of £14 367 per QALY. The key model drivers are the intervention effect on levels of physical activity, quality-of-life gain for high levels of physical activity, the duration of the intervention effects and the period over which effects wane.

Conclusions

The results suggested that such an intervention has the potential to offer a cost-effective use of healthcare-resources for adolescents in the UK at a willingness-to-pay threshold of £20 000 per QALY. The model focused on short-term to medium-term benefits of healthy eating and physical activity exploiting the strong evidence base that exists for this age group. Other benefits in later life, such as reduced cardiovascular risk, are more sensitive to assumptions about the persistence of behavioural change and discounting.

Trail registration number

ISRCTN74109264.

Perspective: Striking a Balance between Planetary and Human Health: Is There a Path Forward?

The global adoption of predominantly plant-based sustainable healthy diets will help reduce the risk of obesity- and malnutrition-related non-communicable diseases while protecting the future health of our planet. This review examines the benefits and limitations of different types of plant-based diets in terms of health and nutrition, affordability and accessibility, cultural (ethical and religious) acceptability, and the environment (i.e., the four pillars underlying sustainable healthy diets). Results suggest that, without professional supervision, traditional plant-based diets (vegan, vegetarian and pescatarian diets) can increase the risk of nutritional deficiencies among infants, children/adolescents, adult females, pregnant/lactating women and the elderly. In contrast, flexitarian diets and territorial diversified diets (TDDs, e.g., Mediterranean and New Nordic diets) that include large quantities of plant-sourced foods, low levels of red meat and moderate amounts of poultry, fish, eggs and dairy can meet the energy and nutrition needs of different populations without the need for dietary education or supplementation. Compared to vegan, vegetarian and pescatarian diets, more diverse flexitarian diets and TDDs are associated with reduced volumes of food waste and may be more acceptable and easier to maintain for people who previously followed western diets. Although flexitarian diets and TDDs have a greater impact on the environment than vegan, vegetarian and pescatarian diets, the negative effects are considerably reduced compared to western diets, especially if diets include locally-sourced seasonal foods. Further studies are required to define more precisely optimal sustainable healthy diets for different populations and to ensure that diets are affordable and accessible to people in all countries.

Pathways to "5-a-day": modeling the health impacts and environmental footprints of meeting the target for fruit and vegetable intake in the United Kingdom

BACKGROUND

Fruit and vegetable consumption in the United Kingdom is currently well below recommended levels, with a significant associated public health burden. The United Kingdom has committed to reducing its carbon emissions to net zero by 2050, and this transition will require shifts towards plant-based diets.

OBJECTIVE

The aim was to quantify the health effects, environmental footprints, and cost associated with 4 different pathways to meeting the United Kingdom's "5-a-day" recommendation for fruit and vegetable consumption.

METHODS

Dietary data based on 18,006 food diaries from 4528 individuals participating in the UK National Diet and Nutrition Survey (2012/13-2016/17) constituted the baseline diet. Linear programming was used to model the hypothetical adoption of the 5-a-day (400 g) recommendation, which was assessed according to 4 pathways differing in their prioritization of fruits versus vegetables and UK-produced versus imported varieties. Increases in fruit and vegetable consumption were substituted for consumption of sweet snacks and meat, respectively. Changes in life expectancy were assessed using the IOMLIFET life table model. Greenhouse gas emissions (GHGEs), blue water footprint (WF), and total diet cost were quantified for each 5-a-day diet.

RESULTS

Achieving the 5-a-day target in the United Kingdom could increase average life expectancy at birth by 7-8 mo and reduce diet-related GHGEs by 6.1 to 12.2 Mt carbon dioxide equivalents/y; blue WFs would change by -0.14 to +0.07 km3/y. Greater reductions in GHGEs were achieved by prioritizing increased vegetable consumption over fruit, whereas the greatest reduction in WF was obtained by prioritizing vegetable varieties produced in the United Kingdom. All consumption pathways increased diet cost (£0.34-£0.46/d).

CONCLUSIONS

Benefits to both population and environmental health could be expected from consumption pathways that meet the United Kingdom's 5-a-day target for fruit and vegetables. Our analysis identifies cross-sectoral trade-offs and opportunities for national policy to promote fruit and vegetable consumption in the United Kingdom.

Designing Nutritionally Adequate and Climate-Friendly Diets for Omnivorous, Pescatarian, Vegetarian and Vegan Adolescents in Sweden Using Linear Optimization

Low-carbon diets can counteract climate change and promote health if they are nutritionally adequate, affordable and culturally acceptable. This study aimed at developing sustainable diets and to compare these with the EAT-Lancet diet. The Swedish national dietary survey Riksmaten Adolescents 2016-2017 was used as the baseline. Diets were optimized using linear programming for four dietary patterns: omnivores, pescatarians, vegetarians and vegans. The deviation from the baseline Riksmaten diet was minimized for all optimized diets while fulfilling nutrient and climate footprint constraints. Constraining the diet-related carbon dioxide equivalents of omnivores to 1.57 kg/day resulted in a diet associated with a reduction of meat, dairy products, and processed foods and an increase in potatoes, pulses, eggs and seafood. Climate-friendly, nutritionally adequate diets for pescatarians, vegetarians and vegans contained fewer foods and included considerable amounts of fortified dairy and meat substitutes. The optimized diets did not align very well with the food-group pattern of the EAT-Lancet diet. These findings suggest how to design future diets that are climate-friendly, nutritionally adequate, affordable, and culturally acceptable for Swedish adolescents with different dietary patterns. The discrepancies with the EAT diet indicate that the cultural dietary context is likely to play an important role in characterizing sustainable diets for specific populations.

Potential health impact of increasing adoption of sustainable dietary practices in Sweden

BACKGROUND

An urgent transition to more sustainable diets is necessary for the improvement of human and planetary health. One way to achieve this is for sustainable practices to become mainstream. We estimated the potential health impact of wider adoption of dietary practices deemed by consumers, researchers and stakeholders in Sweden to be niche, sustainable and with the potential to be scaled up.

METHODS

A life table method was used to estimate the impact - changes in years of life lost (YLL) - over periods of 20 and 30 years in the Swedish population had the practices been adopted in 2010-11, when the last national adult dietary survey was conducted. The practices modelled were reducing red and processed meat (by 25, 50 and 100%), and assuming, for each stage, replacement by an equal weight of poultry/fish and vegetables +/- legumes; reducing milk intake (by 25, 50 and 100%); and reducing sugar-sweetened beverage intake (by 25, 50 and 100%). Using population data together with data on cause-specific mortality and relative risks for diet-disease outcomes, impacts were estimated for each scenario separately and in combination, for the outcomes ischaemic heart disease (IHD), ischaemic stroke, diabetes type 2 and colorectal cancer.

RESULTS

For a "moderate" combination of scenarios (changes at the 50% level), reductions of 513,200 YLL (lower-upper uncertainty estimate 59,400-797,900) could have been achieved over 20 years and 1,148,500 YLL (135,900-1,786,600) over 30 years. The majority (over 90%) of YLLs prevented were related to IHD, and the majority were in men. The singular practice that had the most impact was reducing the intake of red and processed meat and replacing it with a mixture of vegetables and legumes. Reducing milk intake resulted in an increase in YLL, but this was compensated for by other scenarios.

CONCLUSION

If these practices were more widely adopted, they would be expected to lead to improvements in public health in Sweden. Over the long term, this would translate to many premature deaths postponed or prevented from a number of chronic diseases, to the benefit of individuals, society, the climate and the economy.

Conservative to disruptive diets for optimizing nutrition, environmental impacts and cost in French adults from the NutriNet-Santé cohort

Improving the sustainability of diets requires the identification of diets that meet the nutritional requirements of populations, promote health, are within planetary boundaries, are affordable and are acceptable. Here we explore the extent to which dimensions of sustainability could be optimally aligned and identify more sustainable dietary solutions, from the most conservative to the most disruptive, among 12,166 participants of the NutriNet-Santé cohort. We aim to concomitantly lower environmental impacts (including greenhouse gas emissions, cumulative energy demand and land occupation), increase organic food consumption and study departure from observed diets (considered as a proxy for acceptability). From the most conservative to the most disruptive scenario, optimized diets were gradually richer in fruits, vegetables and soya-based products and markedly poorer in animal-based foods and fatty and sweet foods. The contribution of animal protein to total protein intake gradually decreased by 12% to 70% of the observed value. The greenhouse gas emissions from food production for the diets gradually decreased across scenarios (as a percentage of observed values) by 36-86%, land occupation for food production by 32-78% and energy demand by 28-72%. Our results offer a benchmark of scenarios of graded dietary changes against graded sustainability improvements.

A call for urgent action to safeguard our planet and our health in line with the helsinki declaration

In 2015, the Rockefeller Foundation-Lancet Commission launched a report introducing a novel approach called Planetary Health and proposed a concept, a strategy and a course of action. To discuss the concept of Planetary Health in the context of Europe, a conference entitled: "Europe That Protects: Safeguarding Our Planet, Safeguarding Our Health" was held in Helsinki in December 2019. The conference participants concluded with a need for action to support Planetary Health during the 2020s. The Helsinki Declaration emphasizes the urgency to act as scientific evidence shows that human activities are causing climate change, biodiversity loss, land degradation, overuse of natural resources and pollution. They threaten the health and safety of human kind. Global, regional, national, local and individual initiatives are called for and multidisciplinary and multisectorial actions and measures are needed. A framework for an action plan is suggested that can be modified for local needs. Accordingly, a shift from fragmented approaches to policy and practice towards systematic actions will promote human health and health of the planet. Systems thinking will feed into conserving nature and biodiversity, and into halting climate change. The Planetary Health paradigm ‒ the health of human civilization and the state of natural systems on which it depends ‒ must become the driver for all policies.

Public health risk-benefit assessment of red meat in France: Current consumption and alternative scenarios

Consumption of red meat has been associated with the risks of colorectal cancer (CRC), cardiovascular disease (CVD), foodborne-pathogen related diseases and with the potential benefit obtained by reduction of iron deficiency anemia (IDA). Based on probabilistic models, current risks and benefit for the French population were aggregated into a single metric, the disability adjusted life years (DALY). In France, per 100,000 people, current red meat consumption was responsible for a mean of 19 DALYs due to CRC, 21 DALYs to CVD and 7 DALYs to foodborne diseases. Current consumption of iron throughout the diet led to a mean of 15 DALYs due to IDA. To mitigate the risks, scenarios were built per sub-population of age and gender. Among adult and elderly population, the big meat eaters would benefit to adhere to the current recommendation (less than 500 g/w): the risks of CRC and CVD would decrease. Regarding IDA (scenario built with fixed ground beef amount), for young population, a consumption of 375g/w would be sufficient to eliminate the burden while for 25-44 years-old females, 455g/w would reduce IDA, but not entirely. This study highlighted the importance of assessing health risk-benefit per sub-populations and the necessity of communicating the results accordingly.

Climate change mitigation through dietary change: a systematic review of empirical and modelling studies on the environmental footprints and health effects of 'sustainable diets'

The adoption of healthy diets with low environmental impact has been widely promoted as an important climate change mitigation strategy. Typically, these diets are high in plant-sourced and low in animal-sourced and processed foods. Despite the fact that their environmental impacts vary, they are often referred to as 'sustainable diets'. Here we systematically review the available published evidence on the effect of 'sustainable diets' on environmental footprints and human health. Eight databases (OvidSP-Medline, OvidSP-Embase, EBSCO-GreenFILE, Web of Science Core Collection, Scopus, OvidSP-CAB-Abstracts, OvidSP-AGRIS, and OvidSP-Global Health) were searched to identify literature (published 1999-2019) reporting health effects and environmental footprints of 'sustainable diets'. Available evidence was mapped and pooled analysis was conducted by unique combinations of diet pattern, health and environmental outcome. Eighteen studies (412 measurements) met our inclusion criteria, distinguishing twelve non-mutually exclusive sustainable diet patterns, six environmental outcomes, and seven health outcomes. In 87% of measurements (n = 151) positive health outcomes were reported from 'sustainable diets' (average relative health improvement: 4.09% [95% CI -0.10-8.29]) when comparing 'sustainable diets' to current/baseline consumption patterns. Greenhouse gas emissions associated with 'sustainable diets' were on average 25.8%[95%CI -27.0 to -14.6] lower than current/baseline consumption patterns, with vegan diets reporting the largest reduction in GHG-emissions (-70.3% [95% CI: -90.2 to -50.4]), however, water use was frequently reported to be higher than current/baseline diets. Multiple benefits for both health and the environment were reported in the majority (n = 315[76%]) of measurements. We identified consistent evidence of both positive health effects and reduced environmental footprints accruing from 'sustainable diets'. The notable exception of increased water use associated with 'sustainable diets' identifies that co-benefits are not universal and some trade-offs are likely. When carefully designed, evidence-based, and adapted to contextual factors, dietary change could play a pivotal role in climate change mitigation, sustainable food systems, and future population health.

Mapping the co-benefits of climate change action to issues of public concern in the UK: a narrative review

To avoid a 1·5°C rise in global temperatures above preindustrial levels, the next phase of reductions in greenhouse gas emissions will need to be comparatively rapid. Linking the co-benefits of climate action to wider issues that the public are concerned about can help decision makers to prioritise decarbonisation options that increase the chance of public support for such changes, while ensuring that a just transition is delivered. We identified key issues of concern to the UK public by use of Ipsos MORI public opinion data from 2007 to 2020 and used these data to guide a narrative review of academic and grey literature on the co-benefits of climate change action for the UK. Correspondence with civil servants, third sector organisations, and relevant academics allowed us to identify omissions and to ensure policy relevance of the recommendations. This evidence-based Review of the various co-benefits of climate change action for the UK identifies four main areas: health and the National Health Service; security; economy and unemployment; and poverty, housing, and inequality. Associated trade-offs are also discussed. City-level and regional-level governments are particularly well placed to incorporate co-benefits into their decision making because it is at this scale that co-benefits most clearly manifest, and where interventions can have the most immediate effects.

Health impacts and environmental footprints of diets that meet the Eatwell Guide recommendations: analyses of multiple UK studies

OBJECTIVES

To assess the health impacts and environmental consequences of adherence to national dietary recommendations (the Eatwell Guide (EWG)) in the UK.

DESIGN AND SETTING

A secondary analysis of multiple observational studies in the UK.

PARTICIPANTS

Adults from the European Prospective Investigation into Cancer - Oxford(EPIC-Oxford), UK Biobank and Million Women Study, and adults and children aged 5 and over from the National Diet and Nutrition Survey (NDNS).Primary and secondary outcome measures risk of total mortality from Cox proportional hazards regression models, total greenhouse gas emissions (GHGe) and blue water footprint (WF) associated with 'very low' (0-2 recommendations), 'low' (3-4 recommendations) or 'intermediate-to-high' (5-9 recommendations) adherence to EWG recommendations.

RESULTS

Less than 0.1% of the NDNS sample adhere to all nine EWG recommendations and 30.6% adhere to at least five recommendations. Compared with 'very low' adherence to EWG recommendations, 'intermediate-to-high adherence' was associated with a reduced risk of mortality (risk ratio (RR): 0.93; 99% CI: 0.90 to 0.97) and -1.6 kg CO2eq/day (95% CI: -1.5 to -1.8), or 30% lower dietary GHGe. Dietary WFs were similar across EWG adherence groups. Of the individual Eatwell guidelines, adherence to the recommendation on fruit and vegetable consumption was associated with the largest reduction in total mortality risk: an RR of 0.90 (99% CI: 0.88 to 0.93). Increased adherence to the recommendation on red and processed meat consumption was associated with the largest decrease in environmental footprints (-1.48 kg CO2eq/day, 95% CI: -1.79 to 1.18 for GHGe and -22.5 L/day, 95% CI: -22.7 to 22.3 for blue WF).

CONCLUSIONS

The health and environmental benefits of greater adherence to EWG recommendations support increased government efforts to encourage improved diets in the UK that are essential for the health of people and the planet in the Anthropocene.

Review of sustainable diets: are nutritional objectives and low-carbon-emission objectives compatible?

Food systems in developed countries face one major challenge, namely the promotion of diets that are both healthy and generate less greenhouse gas emissions (GHGE). In this article, we review papers evaluating the impact of a change in diets on both health and GHGE. We address the following questions: How big are the health and environmental impacts that could be induced by a switch to healthier diets? In monetary value, what is the relative importance of the health impact and the environmental impact? Is it possible to design an economic policy to increase global welfare that also takes into account the externalities on both health and the environment? Since the way the change in diet is modeled is a key issue, we classify papers according to the methodology used for simulating diet changes: ad hoc scenarios, optimized diets, and economic modeling. We find that it is possible to design economic policies that have positive impacts on both dimension. Because the substitutions/complementarities between food products are complex, it is not granted that a policy targeting one dimension will generate positive effects on the other dimensions. However, given the diversity of substitution and the complementarity possibilities between products, it is possible to design a policy that does improve both dimensions. A carbon-based tax policy that targets the products with a high greenhouse gas content (e.g., meat products) and reinvests the revenues collected with the tax to subsidize the consumption of fruit and vegetables, is likely to have positive effects on both dimensions.

Sustainable and acceptable school meals through optimization analysis: an intervention study

Background

School meals hold considerable potential to shape children’s diets and reduce food-related greenhouse gas emissions (GHGE)—in the short and long term. This study applied linear optimization to develop a GHGE-reduced, nutritionally adequate, and affordable school lunch menu. The effects on food waste, consumption and pupils’ satisfaction with the meals were evaluated.

Methods

A pre-post design was employed to assess the effects of implementing an optimized lunch menu on daily food waste, consumption, and pupils’ school meal satisfaction in three schools (grades 0–9) from one Swedish municipality. A food list containing amounts, prices, nutrient content, and GHGE-values of all foods used for a previously served (baseline) four-week lunch menu was created. Using linear programming, this food list was optimized for minimum deviation and constrained to ensure nutritional adequacy and a reduced climate impact. The optimized food list was developed into a new (intervention) four-week lunch menu by a professional meal planner, following the baseline menu as closely as possible. The baseline and intervention menus were served for four weeks, respectively, with a two week break in between. Prepared, wasted and leftover food were weighed daily by the school kitchen staff during both periods. Interrupted time series analysis assessed mean and slope differences in daily food waste and consumption between the two periods. School lunch satisfaction was assessed with an online questionnaire at baseline and during the intervention.

Results

Optimization resulted in a food list that was 40% lower in GHGE, met all nutrient recommendations for school meals, and cost 11% less compared to baseline. The intervention menu was served as planned, with only minor changes required (for practical reasons). Plate waste, serving waste, consumption and school lunch satisfaction did not differ significantly from baseline, in any of the schools.

Conclusions

The findings demonstrate that school meals can successfully be improved regarding health and environmental sustainability using linear optimization, without negative effects on food waste, consumption or cost. This approach offers the necessary flexibility to tailor menus towards different priorities and could therefore be transferred to other types of meal services.

Trial registration

The trial is registered at clinicaltrials.gov (NCT04168632 Fostering Healthy and Sustainable Diets Through School Meals (OPTIMAT).

Health benefits of policies to reduce carbon emissions

James Milner and colleagues argue that carefully considered policies to lower carbon emissions can also improve health, and we should use these benefits to push for strong climate action

The Role of Health in Households' Balancing Act for Lifestyles Compatible with the Paris Agreement-Qualitative Results from Mannheim, Germany

Household lifestyles are the main drivers of climate change. Climate change mitigation measures directed to households often have substantial health co-benefits. The European mixed-methods study HOPE (HOuseholds' Preferences for reducing greenhouse gas emissions in four European high-income countries) investigates households' preferences for reducing greenhouse gas emissions and particularly researches the role of information on health co-benefits in households' decision making. The results presented in this study are derived from 18 qualitative interviews, conducted with a subsample of households from Mannheim, Germany. The in-depth interviews were transcribed verbatim, analyzed with a qualitative content analysis, supported by NVivo software. They showed that, in order to reduce their greenhouse gas emission in a way compatible with the 1.5 °C goal, households have to undertake a difficult balancing act, considering factors from the individual sphere, such as health co-benefits, as well as from the public sphere, such as (climate) policies. Shared responsibility and equity are important aspects of households. In conclusion, health is an important factor in households' decision making. However, information policies about health co-benefits need to go along with structural policy measures, in order to support households effectively in the implementation of healthy and climate-friendly lifestyles, especially in sectors where behavior change is difficult, like the mobility sector.

Participatory Methods to Identify Perceived Healthy and Sustainable Traditional Culinary Preparations across Three Generations of Adults: Results from Chile's Metropolitan Region and Region of La Araucanía

Traditional diets reflect different cultures and geographical locations, and may provide healthy diet options. In Chile, it is unknown whether traditional culinary preparations are still remembered, let alone consumed. Therefore, we adapted methods to identify traditional culinary preparations for healthy and sustainable dietary interventions. In Chile's Metropolitan Region and the Region of La Araucanía, we collected data on the variety of traditional diets through cultural domain analyses: direct participant observation (n = 5); free listing in community workshops (n = 10); and pile sort activities within semi-structured individual interviews (n = 40). Each method was stratified by age (25-45 year, 46-65 year and ≥ 65 year) and ethnic group (first nations or not). About 600 preparations and single-ingredient foods were identified that differed both in frequency and variety by region. The foods most consumed and liked (n = 24-27) were ranked in terms of sustainability for public nutrition purposes. Methods originally designed to collect information about plants of indigenous peoples can be extended to collect data on the variety of existing traditional culinary preparations, globally. Context, both geographical and cultural, matters for understanding food variety, and its subsequent use in the design of healthy and sustainable diet interventions.

Healthy and Climate-Friendly Eating Patterns in the New Zealand Context

BACKGROUND

The global food system is driving both the climate crisis and the growing burden of noncommunicable disease. International research has highlighted the climate and health co-benefit opportunity inherent in widespread uptake of plant-based diets. Nevertheless, uncertainty remains as to what constitutes healthy and climate-friendly eating patterns in specific world regions.

OBJECTIVES

Using New Zealand as a case study, this research investigates the extent to which potential contextual differences may affect the local applicability of international trends. It further examines the potential for demand-end avenues to support a transition toward a healthier, more climate-friendly food system in New Zealand.

METHODS

A New Zealand-specific life-cycle assessment (LCA) database was developed by modifying cradle to point-of-sale reference emissions estimates according to the New Zealand context. This food emissions database, together with a New Zealand-specific multistate life-table model, was then used to estimate climate, health, and health system cost impacts associated with shifting current consumption to align with dietary scenarios that conform to the New Zealand dietary guidelines (NZDGs).

RESULTS

Whole plant foods, including vegetables, fruits, legumes, and whole grains were substantially less climate-polluting (1.2-1.8 kgCO2e/kg) than animal-based foods, particularly red and processed meats (12-21 kgCO2e/kg). Shifting population-level consumption to align with the NZDGs would confer diet-related emissions savings of 4-42%, depending on the degree of dietary change and food waste minimization pursued. NZDG-abiding dietary scenarios, when modeled out over the lifetime of the current New Zealand population, would also confer large health gains (1.0-1.5 million quality-adjusted life-years) and health care system cost savings (NZ$14-20 billion).

DISCUSSION

Guideline-abiding dietary scenarios, particularly those that prioritize plant-based foods, have the potential to confer substantial climate and health gains. This research shows that major contextual differences specific to New Zealand's food system do not appear to cause notable deviation from global trends, reinforcing recent international research. https://doi.org/10.1289/EHP5996.

Sustainable Diet Dimensions. Comparing Consumer Preference for Nutrition, Environmental and Social Responsibility Food Labelling: A Systematic Review

Global food systems are currently challenged by unsustainable and unhealthy consumption and production practices. Food labelling provides information on key characteristics of food items, thereby potentially driving more sustainable food choices or demands. This review explores how consumers value three different elements of sustainable diets: Comparing consumer response to nutrition information on food labels against environmental and/or social responsibility information. Six databases were systematically searched for studies examining consumer choice/preference/evaluation of nutrition against environmental and/or social responsibility attributes on food labels. Studies were quality assessed against domain-based criteria and reported using PRISMA guidelines. Thirty articles with 19,040 participants met inclusion criteria. Study quality was mixed, with samples biased towards highly-educated females. Environmental and social responsibility attributes were preferred to nutrition attributes in 17 studies (11 environmental and six social), compared to nine where nutrition attributes were valued more highly. Three studies found a combination of attributes were valued more highly than either attribute in isolation. One study found no significant preference. The most preferred attribute was organic labelling, with a health inference likely. Consumers generally have a positive view of environmental and social responsibility food labelling schemes. Combination labelling has potential, with a mix of sustainable diet attributes appearing well-received.

Achieving Healthy and Sustainable Diets: A Review of the Results of Recent Mathematical Optimization Studies

Climate protection and other environmental concerns render it critical that diets and agriculture systems become more sustainable. Mathematical optimization techniques can assist in identifying dietary patterns that both improve nutrition and reduce environmental impacts. Here we review 12 recent studies in which such optimization was used to achieve nutrition and environmental sustainability aims. These studies used data from China, India, and Tunisia, and from 7 high-income countries (France, Finland, Italy, the Netherlands, Sweden, the United Kingdom, and the United States). Most studies aimed to reduce greenhouse gas emissions (10 of 12) and half aimed also to reduce ≥1 other environmental impact, e.g., water use, fossil energy use, land use, marine eutrophication, atmospheric acidification, and nitrogen release. The main findings were that in all 12 studies, the diets optimized for sustainability and nutrition were more plant based with reductions in meat, particularly ruminant meats such as beef and lamb (albeit with 6 of 12 of studies involving increased fish in diets). The amount of dairy products also tended to decrease in most (7 of 12) of the studies with more optimized diets. Other foods that tended to be reduced included: sweet foods (biscuits, cakes, and desserts), savory snacks, white bread, and beverages (alcoholic and soda drinks). These findings were broadly compatible with the findings of 7 out of 8 recent review articles on the sustainability of diets. The literature suggests that healthy and sustainable diets may typically be cost neutral or cost saving, but this is still not clear overall. There remains scope for improvement in such areas as expanding research where there are no competing interests; improving sustainability metrics for food production and consumption; consideration of infectious disease risks from livestock agriculture and meat; and researching optimized diets in settings where major policy changes have occurred (e.g., Mexico's tax on unhealthy food).

Insect Food Products in the Western World: Assessing the Potential of a New 'Green' Market

Although two billion people already eat insects in the world and the benefits of edible insects are well known, these 'green' sources of protein are neither treated as conventional food products nor widely incorporated into Western diets. Using a school-based investigation surveying 161 children, aged 6-15, and 114 of their parents in London, and an online consumer survey with mainly British and French consumers (N = 1,020), this research provides insights into the potential of the insect market in the West. This work supports the idea that incorporating insect food into our diets makes not only environmental but also business sense. A nonnegligible segment of the population surveyed is willing to pay for mealworm minced meat and young children and pre-teens could represent a substantial market segment, as yet unexplored. This analysis points to multiple marketing strategies, such as early exposure, education, reducing the visibility of insect parts, celebrity endorsement, or peer-to-peer marketing, all of which could facilitate the adoption of insect food in the 'mainstream' arena, according to the consumer segment being targeted. Generalizations from these results are restricted to an educated and youthful subset of the potential consumer pool and further work remains to understand the patterns of Western consumer acceptance for the range of insect foods.

Sustainable Diets in the UK—Developing a Systematic Framework to Assess the Environmental Impact, Cost and Nutritional Quality of Household Food Purchases

Sustainable diets should not only respect the environment but also be healthy and affordable. However, there has been little work to assess whether real diets can encompass all three aspects. The aim of this study was to develop a framework to quantify actual diet records for health, affordability and environmental sustainability and apply this to UK food purchase survey data. We applied a Life Cycle Assessment (LCA) approach to detailed food composition data where purchased food items were disaggregated into their components with traceable environmental impact data. This novel approach is an improvement to earlier studies in which sustainability assessments were based on a limited number of “food groups”, with a potentially high variation of actual food items within each group. Living Costs and Food Survey data for 2012, 2013 and 2014 were mapped into published figures for greenhouse gas emissions (GHGE, taking into account processing, transport and cooking) and land use, a diet quality index (DQI) based on dietary guidelines and food cost, all standardised per household member. Households were classified as having a ‘more sustainable’ diet based on GHGE, cost and land use being less than the median and DQI being higher than the median. Only 16.6% of households could be described as more sustainable; this rose to 22% for those in the lowest income quintile. Increasing the DQI criteria to >80% resulted in only 100 households being selected, representing 0.8% of the sample. The framework enabled identification of more sustainable households, providing evidence of how we can move toward better diets in terms of the environment, health, and costs.

Associations between active travel and diet: cross-sectional evidence on healthy, low-carbon behaviours from UK Biobank

OBJECTIVES

To examine whether there are associations between active travel and markers of a healthy, low-carbon (HLC) diet (increased consumption of fruit and vegetables (FV), reduced consumption of red and processed meat (RPM)).

DESIGN

Cross-sectional analysis of a cohort study.

SETTINGS

Population cohort of over 500 000 people recruited from 22 centres across the UK. Participants aged between 40 and 69 years were recruited between 2006 and 2010.

PARTICIPANTS

412 299 adults with complete data on travel mode use, consumption of FV and RPM, and sociodemographic covariates were included in the analysis.

EXPOSURE MEASURES

Mutually exclusive mode or mode combinations of travel (car, public transport, walking, cycling) for non-work and commuting journeys.

OUTCOME MEASURES

Consumption of FV measured as portions per day and RPM measured as frequency per week.

RESULTS

Engaging in all types of active travel was positively associated with higher FV consumption and negatively associated with more frequent RPM consumption. Cycling exclusively or in combination with walking was most strongly associated with increased dietary consumption of FV and reduced consumption of RPM for both non-work and commuting journeys. Overall, the strongest associations were between non-work cycling and FV consumption (males: adjusted OR=2.18, 95% CI 2.06 to 2.30; females: adjusted OR=2.50, 95% CI 2.31 to 2.71) and non-work cycling and RPM consumption (males: adjusted OR=0.57, 95% CI 0.54 to 0.60; females: adjusted OR=0.54, 95% CI 0.50 to 0.59). Associations were generally similar for both commuting and non-work travel, and were robust to adjustment with sociodemographic and behavioural factors.

CONCLUSIONS

There are strong associations between engaging in active travel, particularly cycling, and HLC dietary consumption, suggesting that these HLC behaviours are related. Further research is needed to better understand the drivers and dynamics between these behaviours within individuals, and whether they share common underlying causes.

Optimizing School Food Supply: Integrating Environmental, Health, Economic, and Cultural Dimensions of Diet Sustainability with Linear Programming

There is great potential for reducing greenhouse gas emissions (GHGE) from public-sector meals. This paper aimed to develop a strategy for reducing GHGE in the Swedish school food supply while ensuring nutritional adequacy, affordability, and cultural acceptability. Amounts, prices and GHGE-values for all foods and drinks supplied to three schools over one year were gathered. The amounts were optimized by linear programming. Four nutritionally adequate models were developed: Model 1 minimized GHGE while constraining the relative deviation (RD) from the observed food supply, Model 2 minimized total RD while imposing stepwise GHGE reductions, Model 3 additionally constrained RD for individual foods to an upper and lower limit, and Model 4 further controlled how pair-wise ratios of 15 food groups could deviate. Models 1 and 2 reduced GHGE by up to 95% but omitted entire food categories or increased the supply of some individual foods by more than 800% and were deemed unfeasible. Model 3 reduced GHGE by up to 60%, excluded no foods, avoided high RDs of individual foods, but resulted in large changes in food-group ratios. Model 4 limited the changes in food-group ratios but resulted in a higher number of foods deviating from the observed supply and limited the potential of reducing GHGE in one school to 20%. Cost was reduced in almost all solutions. An omnivorous, nutritionally adequate, and affordable school food supply with considerably lower GHGE is achievable with moderate changes to the observed food supply; i.e., with Models 3 and 4. Trade-offs will always have to be made between achieving GHGE reductions and preserving similarity to the current supply.

Estimation of the burden of disease attributable to red meat consumption in France: Influence on colorectal cancer and cardiovascular diseases

The consumption of red meat has been associated with colorectal cancer (CRC) and cardiovascular disease (CVD) worldwide. The objective of this study was to assess quantitatively the burden of disease of CRC and CVD due to the consumption of red meat in France. A probabilistic risk assessment model quantifying the risk, deaths and disability adjusted life years (DALY) of both outcomes was built. In the model, uncertainty and variability were propagated separately. The model used data on current CRC and CVD incidence and red meat consumption in France, as well as dose-response from epidemiological studies. Results were given by age class and gender. A total of 19 [95% CI = 8-33] DALY per 100,000 people per year for CRC associated with red meat consumption was estimated. For CVD, 21 [95% CI = 12-32] DALY per 100,000 people per year was estimated. The uncertainty was mainly due to the dose-response, as revealed by a sensitivity analysis. A scenario analysis, performed on red meat intake, highlighted that consumption of less than 65 g per day could limit the risk of CRC and CVD in the most affected sub-populations.

Dietary Change Scenarios and Implications for Environmental, Nutrition, Human Health and Economic Dimensions of Food Sustainability

Demand side interventions, such as dietary change, can significantly contribute towards the achievement of 2030 national sustainable development goals. However, most previous studies analysing the consequences of dietary change focus on a single dimension of sustainability (e.g., environment) using a limited number of indicators and dietary scenarios. A multi-dimension and multi-indicator analysis can identify the potential trade-offs. Here, starting from the current food consumption data (year 2011), we first designed nine alternative dietary scenarios (healthy Swiss diet, healthy global diet, vegetarian, vegan, pescatarian, flexitarian, protein-oriented and meat-oriented diets and a food greenhouse gas tax diet). Next we calculated three nutritional quality (nutrient balance score, disqualifying nutrient score, percent population with adequate nutrition), five environmental (greenhouse gas, water, land, nitrogen and phosphorus use), one economic (daily food expenditure) and one human health indicator (DALYs) for current and alternative diets. We found that transition towards a healthy diet following the guidelines of Swiss society of nutrition is the most sustainable option and is projected to result in 36% lesser environmental footprint, 33% lesser expenditure and 2.67% lower adverse health outcome (DALYs) compared with the current diet. On the other extreme, transition towards a meat or protein oriented diet can lead to large increases in diet related adverse health outcomes, environmental footprint, daily food expenditure and a reduction in intakes of essential nutrients (for Vitamin C, Fibre, Potassium and Calcium). We found that shifting to the vegetarian and vegan diet scenarios might lead to a reduction in intakes of certain micronutrients currently supplied primarily by animal-sourced foods (Vitamin B12, Choline and Calcium). Results show that achieving a sustainable diet would entail a high reduction in the intake of meat and vegetable oils and a moderate reduction in cereals, roots and fish products and at the same time increased intake of legumes, nuts, seeds, fruits and vegetables. We identify several current data and research gaps that need to be filled in order to get more accurate results. Overall, our analysis underscores the need to consider multiple indicators while assessing the dietary sustainability and provides a template to conduct such studies in other countries and settings. Future efforts should focus on assessing the potential of different interventions and policies that can help transition the population from current to sustainable dietary patterns.

[Health Co-benefits of climate change mitigation measures-how houeseholds and policy makers can benefit]

In discussions on climate change and health, negative impacts of climate change usually dominate the discussion. However to motivate households and policy makers to climate action, one should also point out the health opportunities of climate change mitigation measures.We draw on the current literature to present the concept of health co-benefits of climate change mitigation measures (A). In the empirical part of the paper we first use a quantitative and qualitative text analysis to look at the link of climate change and health in EU legislation from 1990-2015 (B). We then describe results from qualitative in-depth interviews with 18 German households, in which we investigate how knowledge of health co-benefits influences households in implementing climate action. The interviews were part of a bigger European mixed-methods study.A: From the household perspective, we define direct health co-benefits, which can be influenced and experienced by an individual, and indirect health co-benefits, which are dependent on societal action. B: Health is mentioned in EU climate change legislation. However, EU legislation only touches upon health co-benefits in general and doesn't mention direct health co-benefits at all. C: Households consider health co-benefits in their lifestyle decisions. Yet, as there are many determinants of lifestyle, information on health co-benefits alone does not seem to be sufficient to trigger climate friendly and healthy behavior.First, synergies between health and climate change mitigation need to be recognized on a political level. Then, effective intersectoral policies need to be implemented to support households on multiple levels in implementing healthy and climate-friendly lifestyles.

Integrating Agriculture and Health Research for Development: LCIRAH as an Interdisciplinary Programme to Address a Global Challenge

The multiple burdens of persistent undernutrition and micronutrient deficiencies, along with the rapidly growing rates of overweight, obesity, and associated chronic diseases, are major challenges globally. The role of agriculture and the food system in meeting these challenges is very poorly understood. Achieving food security and addressing malnutrition in all its forms, a Sustainable Development Goal, requires an understanding of how changing food systems affect health outcomes and the development of new tools to design and evaluate interventions. An interinstitutional programme to address this interdisciplinary research challenge is described. Over the past seven years, the Leverhulme Centre for Integrative Research on Agriculture and Health has built a portfolio of successful and innovative research, trained a new cadre of interdisciplinary researchers in "Agri-Health," and built an international research community with a particular focus on strengthening research capacity in low- and middle-income countries. The evolution of this programme is described, and key factors contributing to its success are discussed that may be of general value in designing interdisciplinary research programmes directed at supporting global development goals.

Healthy and sustainable diets that meet greenhouse gas emission reduction targets and are affordable for different income groups in the UK

OBJECTIVE

To model dietary changes required to shift the UK population to diets that meet dietary recommendations for health, have lower greenhouse gas emissions (GHGE) and are affordable for different income groups.

DESIGN

Linear programming was used to create diets that meet dietary requirements for health and reduced GHGE (57 and 80 % targets) by income quintile, taking account of food budgets and foods currently purchased, thereby keeping dietary change to a minimum.Setting/ParticipantsNutrient composition, GHGE and price data were mapped to 101 food groups in household food purchase data (UK Living Cost and Food Survey (2013), 5144 households).

RESULTS

Current diets of all income quintiles had similar total GHGE, but the source of GHGE differed by types of meat and amount of fruit and vegetables. It was possible to create diets with a 57 % reduction in GHGE that met dietary and cost restraints in all income groups. In the optimised diets, the food sources of GHGE differed by income group due to the cost and keeping the level of deviation from current diets to a minimum. Broadly, the changes needed were similar across all groups; reducing animal-based products and increasing plant-based foods but varied by specific foods.

CONCLUSIONS

Healthy and lower-GHGE diets could be created in all income quintiles but tailoring changes to income groups to minimise deviation may make dietary changes more achievable. Specific attention must be given to make interventions and policies appropriate for all income groups.

Greenhouse gas emissions and water footprints of typical dietary patterns in India

Agriculture is a major contributor to India's environmental footprint, particularly through greenhouse gas (GHG) emissions from livestock and fresh water used for irrigation. These impacts are likely to increase in future as agriculture attempts to keep pace with India's growing population and changing dietary preferences. Within India there is considerable dietary variation, and this study therefore aimed to quantify the GHG emissions and water usage associated with distinct dietary patterns. Five distinct diets were identified from the Indian Migration Study - a large adult population sample in India - using finite mixture modelling. These were defined as: Rice & low diversity, Rice & fruit, Wheat & pulses, Wheat, rice & oils, Rice & meat. The GHG emissions of each dietary pattern were quantified based on a Life Cycle Assessment (LCA) approach, and water use was quantified using Water Footprint (WF) data. Mixed-effects regression models quantified differences in the environmental impacts of the dietary patterns. There was substantial variability between diets: the rice-based patterns had higher associated GHG emissions and green WFs, but the wheat-based patterns had higher blue WFs. Regression modelling showed that the Rice & meat pattern had the highest environmental impacts overall, with 0.77 (95% CI 0.64-0.89) kg CO2e/capita/day (31%) higher emissions, 536 (95% CI 449-623) L/capita/day (24%) higher green WF and 109 (95% CI 85.9-133) L/capita/day (19%) higher blue WF than the reference Rice & low diversity pattern. Diets in India are likely to become more diverse with rising incomes, moving away from patterns such as the Rice & low diversity diet. Patterns such as the Rice & meat diet may become more common, and the environmental consequences of such changes could be substantial given the size of India's population. As global environmental stress increases, agricultural and nutrition policies must recognise the environmental impacts of potential future dietary changes.

Perspective: Reductionist Nutrition Research Has Meaning Only within the Framework of Holistic and Ethical Thinking

Today, it seems that nutrition is in a state of great confusion, especially for the general public. For decades, some nutrients (e.g., cholesterol, saturated fats, sugars, gluten, salt) and food groups (e.g., dairy, cereals, meats) have been regularly denigrated. In this position paper, we hypothesize that such a state of confusion is mainly the result of the reductionist paradigm applied to nutrition research for more than a century, and by being pushed to its extreme, this perspective has led to accusations about some nutrients and foods. However, the real issue is about foods taken as a whole and therefore about their degree of processing, which affects both the food matrix and composition. Indeed, we eat whole foods, not nutrients. Therefore, the objectives of this article are to emphasize the need for more holistic approaches in nutrition to preserve our health, animal welfare, and planet. We propose to first redefine the food health potential on a holistic basis and then to show that reductionism and holism are interconnected approaches that should coexist. Then, we try to explain how extreme reductionism has been disconnected from reality and ethical considerations and has ultimately led to environmental degradation and loss of biodiversity, notably through very specific crops, and to an increased prevalence of chronic diseases. Furthermore, to address the confusion of the general public and to simplify nutritional messages, we propose 3 holistic golden rules based on scientific evidence to protect human health, animal welfare, and the environment (climate and biodiversity). Finally, we try to show how these 3 rules can be easily applied worldwide while respecting the environment, cultural traditions, and heritage.

Mathematical Optimization to Explore Tomorrow's Sustainable Diets: A Narrative Review

A sustainable diet is, by definition, nutritionally adequate, economically affordable, culturally acceptable, and environmentally respectful. Designing such a diet has to integrate different dimensions of diet sustainability that may not be compatible with each other. Among multicriteria assessment methods, diet optimization is a whole-diet approach that simultaneously combines several metrics for dimensions of diet sustainability. This narrative review based on 67 published studies shows how mathematical diet optimization can help with understanding the relations between the different dimensions of diet sustainability and how it can be properly used to identify sustainable diets. Diet optimization aims to find the optimal combination of foods for a population, a subpopulation, or an individual that fulfills a set of constraints while minimizing or maximizing an objective function. In the studies reviewed, diet optimization was used to examine the links between dimensions of diet sustainability, identify the minimum cost or environmental impact of a nutritionally adequate diet, or identify food combinations able to combine ≥2 sustainability dimensions. If some constraints prove difficult to fulfill, this signals an incompatibility between nutrient recommendations, over-monotonous food-consumption patterns, an inadequate supply of nutrient-rich foods, or an incompatibility with other dimensions. If diet optimization proves successful, it can serve to design nutritionally adequate, culturally acceptable, economically affordable, and environmentally friendly diets. Diet optimization results can help define dietary recommendations, tackle food security issues, and promote sustainable dietary patterns. This review emphasizes the importance of carefully choosing the model parameters (variables, objective function, constraints) and input data and the need for appropriate expertise to correctly interpret and communicate the results. Future research should make improvements in the choice of metrics used to assess each aspect of a sustainable diet, especially the cultural dimension, to improve the practicability of the results.