Modelling impacts of a salt and sugar tax on hypothetical intra-category food substitutions, BMI and environmental footprints in the UK population.

PURPOSE: Taxes on unhealthy foods can help improve population health in the United Kingdom (UK), but the health effects of food substitutions resulting from these taxes are often unclear. We investigated the potential impacts of a salt and sugar tax on hypothetical intra-category food substitutions, cost, body-mass index (BMI), and environmental footprints. METHODS: Purchase panel data from Kantar (2017) were used to determine the most popular foods high in salt or sugar within eight 'salt-intensive'/'sugar-intensive' food categories. Within food categories, the most popular lower salt (≤ 1.5 g salt/100 g product) and lower sugar (≤ 22.5 g sugar/100 g product) substitutes were also identified. Hypothetical swaps between high salt/sugar foods and lower salt/sugar substitutes were explored, focusing on changes to cost, caloric intake and BMI, and environmental impacts in the UK population. RESULTS: The suggested intra-category substitutions were largely like-for-like and did not accrue an added overall cost to consumers. The substitutions reduced calorie intake by about 200 kcal/day and lowered the prevalence of overweight and obesity in the UK from approximately 60-65% to about 40-45%. The proposed food substitutions led to a total reduction of -2.7Mt of greenhouse gases, ∼ -500.000 ha of land, -0.5km3 of blue water, -12km3 of scarcity weighted water, ∼ -12.000t of phosphorus, and nearly - 14.000t of sulphur dioxide over one year for the UK population due to reductions in calorie intake. CONCLUSION: Food substitutions following a tax on salt and sugar could lead to significant benefits for health and the environment, without necessarily resulting in major changes to people's expenditure on familiar salty and sugary snacks.

Investigating intervention components and their effectiveness in promoting environmentally sustainable diets: a systematic review.

Global food systems contribute 30% of global greenhouse gas emissions, threatening the global temperature targets of the Paris Agreement. Diets in high-income countries exceed the recommendations for animal-based foods, whereas consumption of fruits and vegetables is below recommendations. Shifting to a more plant-based diet can reduce up to 30% of greenhouse gas emissions from diet and also reduce risk of chronic disease. Interventions addressing sustainable dietary behaviour, defined by a shift in dietary patterns and food-waste practices, could therefore improve population and planetary health, but knowledge of the interventions that are likely to be most effective in changing sustainable dietary behaviour is so far limited. This systematic review aimed to investigate, classify, and assess the effectiveness of interventions that promote environmentally sustainable diets in high-income countries. We searched MEDLINE, Embase, PsycINFO, and Cumulative Index to Nursing and Allied Health Literature for randomised controlled trials and quasi-experimental trials published from inception until June 16, 2022, evaluating the effectiveness of any intervention promoting environmentally sustainable dietary behaviour. Studies were eligible for inclusion if they included adults and children from high-income countries (as defined by the World Bank classification) and used individual-level behaviour change interventions. Online choice experiments and studies reporting results on only change in fruit and vegetable consumption were excluded. Interventions were classified using the nine intervention functions of the behaviour change wheel. Data were extracted on number of participants, intervention characteristics, diet change (eg, meat consumption and fruit and vegetable intake), food waste, greenhouse gas emissions, and health outcomes. 13 studies were identified and included in the systematic review. Articles were from six different countries (ie, Canada, the USA, Germany, the UK, the Netherlands, Italy). Six of the nine intervention functions of the behaviour change wheel were used. Interventions using education had the most robust evidence base, whereas interventions using persuasion had the strongest effect on reducing meat consumption. Overall, interventions using education in combination with other factors were most successful. Five studies had high risk of bias, five had some concerns of bias, and three had low risk of bias. This systematic review provides insight into the effectiveness of behavioural interventions to meet health and climate change goals through promotion of environmentally sustainable diets. Evidence supports the use of multicomponent interventions through education, persuasion, and environmental restructuring to provide opportunity for change. Little high-quality research was available, and more robustly designed intervention studies are needed to inform future guidelines and policies.

Addressing future food demand in The Gambia: can increased crop productivity and climate change adaptation close the supply-demand gap?

With rising demand for food and the threats posed by climate change, The Gambia faces significant challenges in ensuring sufficient and nutritious food for its population. To address these challenges, there is a need to increase domestic food production while limiting deforestation and land degradation. In this study, we modified the FABLE Calculator, a food and land-use system model, to focus on The Gambia to simulate scenarios for future food demand and increasing domestic food production. We considered the impacts of climate change on crops, the adoption of climate change adaptation techniques, as well as the potential of enhanced fertiliser use and irrigation to boost crop productivity, and assessed whether these measures would be sufficient to meet the projected increase in food demand. Our results indicate that domestic food production on existing cropland will not be sufficient to meet national food demand by 2050, leading to a significant supply-demand gap. However, investments in fertiliser availability and the development of sustainable irrigation infrastructure, coupled with climate change adaptation strategies like the adoption of climate-resilient crop varieties and optimised planting dates, could halve this gap. Addressing the remaining gap will require additional strategies, such as increasing imports, expanding cropland, or prioritising the production of domestic food crops over export crops. Given the critical role imports play in The Gambia's food supply, it is essential to ensure a robust flow of food imports by diversifying partners and addressing regional trade barriers. Our study highlights the urgent need for sustained investment and policy support to enhance domestic food production and food imports to secure sufficient and healthy food supplies amidst growing demand and climate change challenges. Supplementary Information: The online version contains supplementary material available at 10.1007/s12571-024-01444-1.

Mapping the evidence of novel plant-based foods: a systematic review of nutritional, health, and environmental impacts in high-income countries.

CONTEXT: Shifting from current dietary patterns to diets rich in plant-based (PB) foods and lower in animal-based foods (ABFs) is generally regarded as a suitable strategy to improve nutritional health and reduce environmental impacts. Despite the recent growth in supply of and demand for novel plant-based foods (NPBFs), a comprehensive overview is lacking. OBJECTIVES: This review provides a synthesis of available evidence, highlights challenges, and informs public health and environmental strategies for purposeful political decision-making by systematically searching, analyzing, and summarizing the available literature. DATA SOURCES: Five peer-reviewed databases and grey literature sources were rigorously searched for publications. DATA EXTRACTION: Study characteristics meeting the inclusion criteria regarding NPBF nutrient composition and health and environmental outcomes in high-income countries were extracted. DATA ANALYSIS: Fifty-seven peer-reviewed and 36 grey literature sources were identified; these were published in 2016-2022. NPBFs typically have substantially lower environmental impacts than ABFs, but the nutritional contents are complex and vary considerably across brands, product type, and main primary ingredient. In the limited evidence on the health impacts, shifts from ABFs to PB meats were associated with positive health outcomes. However, results were mixed for PB drinks, with links to micronutrient deficiencies. CONCLUSION: If carefully selected, certain NPBFs have the potential to be healthier and nutrient-rich alternatives to ABFs and typically have smaller environmental footprints. More disaggregated categorization of various types of NPBFs would be a helpful step in guiding consumers and key stakeholders to make informed decisions. To enable informed policymaking on the inclusion of NPBFs in dietary transitions as part of a wider net-zero and health strategy, future priorities should include nutritional food standards, labelling, and subdivisions or categorizations of NPBFs, as well as short- and long-term health studies evaluating dietary shifts from ABFs to NPBFs and standardized environmental impact assessments, ideally from independent funders.

An umbrella review of health co-benefits from actions to reduce greenhouse gas emissions.

BACKGROUND: There have been many modelled studies of potential health co-benefits from actions to reduce greenhouse gas emissions, but so far there have been no large-scale attempts to compare the magnitude of health and climate effects across sectors, countries, and study designs. METHODS: As part of the Pathfinder Initiative project an umbrella review of studies was done, and 26 previous reviews were identified with 57 primary studies included. Studies included in the review were required to have quantified changes in greenhouse gas emissions and health effects (or risk factors) from defined actions to reduce climate effects. Study data were extracted and harmonised by standardising impact measures per 100 000 of the national population (or urban population for city-level actions), averaging effects over a 1-year period and aggregating actions into their respective sectors by use of a predefined framework. FINDINGS: From 200 mitigation actions, the majority were in the agriculture, forestry, and land use sector (103 actions [52%]), followed by the transport sector (43 actions [22%]). The largest effects on greenhouse gas emissions were seen from actions in the energy sector, and these actions also had substantial health co-benefits in lower middle-income countries, although benefits were smaller in high-income settings. The greatest health benefits were seen from actions to change diets and introduce clean cookstoves. The major pathways to health were through reduced air pollution, healthier diets, and increased physical activity from switching to active travel modes. Effect sizes tended to be larger from national modelling studies and smaller from localised or implemented actions. INTERPRETATION: The potential co-benefits to health from actions to reduce climate change are large, but most evidence still comes from modelling studies and from high-income and middle-income countries. There are also major context-dependent differences in the magnitude of effects found, so actions need to be tailored to the local context and careful attention needs to be paid to potential trade-offs and spillover effects. FUNDING: The Wellcome Trust and the Oak Foundation.

Barriers to Adopting a Plant-Based Diet in High-Income Countries: A Systematic Review.

Adopting a plant-based diet (PBD) has been shown to reduce the risk of developing certain diseases and is linked to environmental benefits. This review synthesises the evidence on the barriers adults aged 18 to 65 living in high-income countries (HIC) may experience when adopting a PBD. A systematic literature review was conducted using four search databases: Medline, Embase, Global Health, and Web of Science. Barriers were mapped to behaviour change strategies using the COM-B model. Ten studies were included in the final review, including 1740 participants. Five were qualitative, four were cross-sectional, and one was a pre- and-post-intervention study. In total, 40 barriers were identified and synthesised into 11 themes: financial, lack of knowledge, emotional, health, convenience, social, enjoyment of meat, environmental, accessibility, personal ability, and media. Of the 40 barriers, nutritional intake/requirements (categorised into the "health" theme) had the most evidence. This barrier encompassed concerns around being able to meet nutritional needs if an individual were to adopt a PBD. Habits (in the "personal ability" theme), which included established eating habits and habitual behaviours relating to animal-source foods, had the second most evidence alongside the barrier of not knowing what to eat as part of a PBD (in the "lack of knowledge" theme). Education interventions and communication/marketing policies were the behaviour change mechanisms mapped onto these barriers. Future interventions should focus on informing individuals about what to consume as part of a nutritionally balanced PBD and facilitating habitual dietary change.

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.