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

Abstract

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.

Association between the socio-economic status of households and a more sustainable diet

“…Similar to the procedure used by Masset et al in France (33) and Wrieden et al in the UK (34) , the median of the dietary carbon footprint, dietary water footprint, DQI (all standardised per an adult man) and dietary costs of the households were calculated for each year of the data in our study (2016, 2017 and 2018). In addition, the households were considered to have a more sustainable diet based on the dietary carbon footprint, dietary water footprint, dietary costs lower than the median and DQI higher than the median; the other households were assumed to have a less sustainable diet.…”

“…Nevertheless, a higher socio-economic status has been reported to increase the consumption of unhealthy food groups in some cases (19) . Since dietary behaviours are considerably associated with socioeconomic indices (20) , the sustainability of a diet may also be affected by the SES of the general population (21) . Given the novelty of the concept of diet sustainability, few studies have been conducted in this regard, and it is essential to determine the most nutritionally sustainable options in various socio-economic groups.…”

Indicators and Recommendations for Assessing Sustainable Healthy Diets

“…In recent years, there has been an increase in the number of systematic reviews focused on sustainable and healthy diets, most of which also have a specific scope. For instance, some of the reviews have a limited geographical reach, focusing on one country such as the UK [15] or the USA [16]. Other reviews focus on a specific domain such as mathematical optimization studies [17] or labeling schemes [18].…”

“…Other reviews focus on a specific domain such as mathematical optimization studies [17] or labeling schemes [18]. Most reviews have a specific environmental scope, analyzing a single environmental aspect [19,20] or two or three environmental resources [15,21,22]. Some leave socioeconomic aspects out of the scope of review, instead focusing on the interlinkages between the environment and diets [23,24].…”

Environmental Implications of Taiwanese Oolong Tea and the Opportunities of Impact Reduction

“…It is also a common tool utilized to investigate the environmental portfolio of agricultural and food industry in order to verify the primary impact contributors [9][10][11][12][13][14]. As LCA can account for impact footprints under different scenarios, it has also been employed to quantify environmental implications associated with the change of consumption behaviors [15][16][17], and to identify best management practices for mitigating the impact footprint of a product or service [18][19][20]. The development of LCA is believed to have emanated from the need for identifying alternative packaging designs in the beverage industry around 1960s [21].…”