Health Impacts and Environmental Footprints of Diets That Meet the Eatwell Guide Recommendations: Analyses of Multiple UK Studies
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Open access Original research BMJ Open: first published as 10.1136/bmjopen-2020-037554 on 26 August 2020. Downloaded from Health impacts and environmental footprints of diets that meet the Eatwell Guide recommendations: analyses of multiple UK studies Pauline Scheelbeek ,1,2 Rosemary Green,1,2 Keren Papier,3 Anika Knuppel,3 Carmelia Alae- Carew,2 Angela Balkwill,3 Timothy J Key,3 Valerie Beral,3 Alan D Dangour1,2 To cite: Scheelbeek P, ABSTRACT Strengths and limitations of this study Green R, Papier K, et al. Health Objectives To assess the health impacts and impacts and environmental environmental consequences of adherence to national ► This is the first study (in a UK context) using empir- footprints of diets that dietary recommendations (the Eatwell Guide (EWG)) in the meet the Eatwell Guide ical data to study health impacts and multiple envi- UK. recommendations: analyses of ronmental consequences of sustainable diets. Design and setting A secondary analysis of multiple multiple UK studies. BMJ Open ► The study uses multiple high- quality datasets with observational studies in the UK. 2020;10:e037554. doi:10.1136/ a total of 557 722 participants for health outcomes Participants Adults from the European Prospective bmjopen-2020-037554 and 5747 participants for environmental footprints. Investigation into Cancer - Oxford(EPIC- Oxford), UK Biobank ► The provided methods can be replicated in other ► Prepublication history and and Million Women Study, and adults and children aged 5 additional material for this settings and the Eatwell Guide dietary recommen- and over from the National Diet and Nutrition Survey (NDNS). paper are available online. To dations share many features of healthy lower envi- Primary and secondary outcome measures risk of total view these files, please visit ronmental impact diets. mortality from Cox proportional hazards regression the journal online (http:// dx. doi. ► Despite several sensitivity analyses, there might be models, total greenhouse gas emissions (GHGe) and org/ 10. 1136/ bmjopen- 2020- residual confounding (ie, unmeasured differences blue water footprint (WF) associated with ‘very low’ (0–2 037554). between people who eat different diets) distorting recommendations), ‘low’ (3–4 recommendations) or our findings. Received 12 February 2020 ‘intermediate- to- high’ (5–9 recommendations) adherence ► Although the evidence base and quality of methods http://bmjopen.bmj.com/ Revised 15 June 2020 to EWG recommendations. and metrics for environmental footprints are rap- Accepted 03 July 2020 Results Less than 0.1% of the NDNS sample adhere to idly improving, uncertainty about the exact mea- all nine EWG recommendations and 30.6% adhere to at surements of water footprints and greenhouse gas least five recommendations. Compared with ‘very low’ emissions of food items and diets in general remain. 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 CO eq/day (95% CI: −1.5 to −1.8), or 30% lower 2 health and safeguarding environmental dietary GHGe. Dietary WFs were similar across EWG sustainability for future generations. Current on September 28, 2021 by guest. Protected copyright. adherence groups. Of the individual Eatwell guidelines, diets are associated with a high burden of © Author(s) (or their adherence to the recommendation on fruit and vegetable employer(s)) 2020. Re- use disease: globally ~1.9 billion adults are over- consumption was associated with the largest reduction in 1 permitted under CC BY. total mortality risk: an RR of 0.90 (99% CI: 0.88 to 0.93). weight or obese, 462 million are underweight Published by BMJ. Increased adherence to the recommendation on red and and over 30% of the world’s population suffers 1 2 Centre on Climate Change & processed meat consumption was associated with the from deficiencies of essential nutrients. The Planetary Health, London School largest decrease in environmental footprints (−1.48 kg of Hygiene & Tropical Medicine, food system that produces these diets is also CO eq/day, 95% CI: −1.79 to 1.18 for GHGe and −22.5 L/ London, United Kingdom 2 responsible for 21%–37% of global green- 3 2Department of Population day, 95% CI: −22.7 to 22.3 for blue WF). house gas emissions (GHGe) and agriculture Health, London School of Conclusions The health and environmental benefits of alone accounts for ~70% of fresh water with- Hygiene & Tropical Medicine, greater adherence to EWG recommendations support drawal.4 While food system GHGe contribute London, United Kingdom increased government efforts to encourage improved diets 3 to global climate change problems regard- Nuffield Department of in the UK that are essential for the health of people and the Population Health, Oxford planet in the Anthropocene. less of location of production, food system University, Oxford, UK water use is highly location specific: with approximately half of all countries classified Correspondence to BACKGROUND as ‘water scarce’—and a number of water safe Dr Pauline Scheelbeek; Diets are likely to play a crucial role in the countries projected to become water scarce Pauline. Scheelbeek@ lshtm. Anthropocene in supporting population ac. uk by 20405—origin of food supply is a crucial Scheelbeek P, et al. BMJ Open 2020;10:e037554. doi:10.1136/bmjopen-2020-037554 1 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037554 on 26 August 2020. Downloaded from consideration when considering the sustainability of food these are subject to many assumptions related to the system water use. substitutions between food groups inherent to the dietary There is an urgent need for significant transformations change. To date, no study has been conducted using of the food system to produce diets that address both empirical dietary data (of large- scale cohort studies) to health and environmental concerns, and evidence on the assess ‘real- world’ composition of diets that are in adher- recommended composition of these diets is expanding ence with the EWG, which could substantially improve rapidly.6 7 While the specific composition of such diets has the uncertainty of estimation of the associated change in been shown to vary considerably culturally and region- dietary GHGe. Furthermore, to date, no analysis of the ally compared with existing consumption patterns, these WF of EWG adherence has been published. diets typically have substantially greater plant- based food In this report, we use high- quality data from three large content as well as no more than moderate content of prospective UK cohort studies to assess the health impacts animal sourced foods (eg, meat and dairy).6 8 9 associated with adherence to EWG dietary guidelines; The UK food system is no exception to these concerns and using nationally representative dietary intake data, for sustainability, and many transformative changes need we estimate the environmental footprints of UK diets with to be made to make it more sustainable, resilient and varying degrees of adherence to EGW recommendations. healthy. Currently 64% of the adult population in the UK are overweight or obese,10 and only 29% of adults and 18% of children between 5 and 15 years of age meet the METHODS recommended fruit and vegetable intake of ‘5 a day’.10 At Datasets the same time, water use of UK diets is on average 2757 L/ We used four high-quality data sources in this paper 11 capita/day, which is below the global average of 3167 L, (detailed description of each database provided in online but half of the national blue (surface and ground) water supplementary appendix 1). The databases from Euro- 3 footprint (WF)—15.0 million m /day—is imported (ie, pean Prospective Investigation into Cancer - Oxford embedded in imported foods from elsewhere) from (EPIC- Ox),26 UK Biobank (UKB)27 and the Million 12 13 countries with water scarcity. Furthermore, GHGe of Women Study (MWS)28 contain comprehensive health average UK diets were found to be 1210 kg CO2eq/capita/ information, linked death registration data as well as year as compared with an European Union average of dietary intake data. These three datasets were used to 14 1070 kg CO2eq/capita/year. Evidence suggests that 17% estimate the associations with health of adherence to of emissions could be avoided when the population were EWG recommendations. Details on the specific datasets 15 to shift to WHO dietary guidelines. have been published elsewhere. Briefly, participants in Governments are increasingly including both health the MWS were recruited from women invited for breast and environmental considerations in their recom- cancer screening in England and Scotland between 1996 mended dietary guidelines. In the UK, Public Health and 2001. Dietary intake was collected using semiquan- http://bmjopen.bmj.com/ England produced the ‘Eatwell Guide’ (EWG) as a titative questions and total mortality was determined ‘policy tool to define government recommendations on using death records. We used data from 464 078 partici- 16 eating healthily and achieving a balanced diet’. From pants of the MWS database. In the EPIC- Ox study, which a health perspective, the EWG promotes, for example, involves both male and female participants, dietary intake cereals, potatoes, fruit, vegetable and fibre consumption, was collected using a Food Frequency questionnaire, while recommending a limited consumption of sugar and while total mortality was ascertained using death record 17 processed meats. Adhering to these individual guide- linkage. We used data from 40 030 men and women of lines has been associated with several health benefits the EPIC- Ox database. For the UKB study, middle- aged on September 28, 2021 by guest. Protected copyright. 18 including improved cardiovascular health and reduced adults were recruited between 2006 and 2010. A subsa- 19 20 cancer risk. From an environmental perspective, the mple completed a minimum of three 24 hours dietary EWG mentions the importance of a ‘balance of healthier recall questionnaires.