LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

GROUP 3, SESSION A: LABELLING, CONSUMERS, DIET 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
69. Assessment of the environmental impact of dietary intake habits in
the UK
Janet Kyle 1,* , Jennie Macdiarmid 2 and Tony Craig 3
1 Public Health Nutrition Research Group, Institute of Applied Health Sciences, University of Aberdeen, Foresterhill,
Aberdeen, AB25 2ZD, UK, 2 Rowett Institute of Nutrition and Health, University of Aberdeen, UK,
3 James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK, * Corresponding author. E-mail:
j.kyle@abdn.ac.uk
The food system is estimated to account for 18-20% of total UK greenhouse gas (GHG) emissions, increasing
to 30% factoring land use change (Audsley et al 2009), and food consumption habits make an important
contribution to these emissions. With the introduction of legally binding commitments to reduce GHGE; the
UK Climate Change Act (2008) set targets to reduce GHGE by at least 34% by 2020, this will require not
only efficiency savings in food production and processing, but also adoption of lower impact diets by consumers.
However, in the UK, few studies have assessed the impact of actual dietary habits and the environmental
impact, measured in the form of GHG emissions. The current study aimed to investigate the potential
of assessing the environmental impact of dietary intake habits using a novel approach to measuring and ranking
the environmental impact of food consumption into high, medium and low levels of emissions and compare
this with the nutritional quality of the diet.
A random sample to people living in the South West of Scotland were asked to completed an anonymised
postal survey, 527 people, average age 58y (range 20-90y) returned the questionnaires. Habitual diet was
measured using a food frequency questionnaire (FFQ) (www.foodfrequency.org), which asks for the frequency
of consumption of 170 food and drink items and has been previously validated for dietary assessment.
Food and nutrient intake and environmental impact were determined by linking, the FFQ response
information to an in-house food nutrient composition and food related GHG emissions database. Estimation
of average daily GHG emissions acted as a marker of environmental impact.
GHG emissions values for food items ‘as eaten’ were calculated from raw food commodities data from one
of the most comprehensive lists of GHG emissions in the UK (Audsley et al 2009). These food commodity
data did not represent the full ‘cradle to grave’ life cycle analysis (LCA), but rather the average GHG emissions
for the production of raw food commodities up to the regional distribution centre (RDC). The RDC
was described as a nominal boundary of agricultural and food ingredient production up to the point of distribution
in the UK and estimated to account on average for 56% of the total LCA GHG emissions. The later
stages of processing raw basic ingredients into edible food products ready for consumption were not included.
These data were harmonised with the nutrient composition data to reflect food as eaten, with adjustments
for edible portion, cooking gains and losses, and production of composite dishes and food products,
such as lasagne, crisps and cakes, employing a proportion of ingredients approach,. It is important to note for
example that GHG emissions for cooked meat will in relative terms increase due to weight loss whilst cooking,
while the emissions for rice will fall with cooking due to weight gains through hydration. However it is
important to highlight there is a lack of complete ‘cradle to grave’ LCA for commonly consumed foods.
Preliminary results indicate that though, as expected, increasing energy intake and levels of GHG emissions
are closed linked, the actual quality of the diet from a health perspective does not appear to diminish. For
example, the relative contribution of fat (34% of total energy), protein (16% of total energy), to total energy
intake remains unchanged with increasing levels of GHG emissions from the diet. This study has lead to
deeper insights into the interactions between diet, environment and health which will contribute to development
of the population based approaches to reducing the environmental impact of dietary intake.
References
Audsley E, Brander M, Chatterton J, Murphy-Bokern D, Webster C, Williams A., 2009. How Low Can We
Go? An assessment of greenhouse gas emissions from the UK food system and the scope for reduction by
2050. WWF-UK.
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