Background healthy and sustainable diets


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Background healthy and sustainable diets. Talk for PhD Students of the Environment and Food Security Theme - University of Aberdeen

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Background healthy and sustainable diets

  1. 1. Implications of Achieving Healthy and Environmentally Sustainable Diets on the Demands for Future Land Use in Scotland Henri de Ruiter University of Aberdeen James Hutton Institute
  2. 2. Healthy and Sustainable Diets  In January, I stayed in a Scottish Bed & Breakfast  This was my breakfast:
  3. 3. Healthy and Sustainable Diets  When I first came here in October, I learned about more notorious things:  The deep-fried Mars bar “We conclude that Scotland's deep-fried Mars bar is not just an urban myth.” “Encouragingly, we did also find some evidence of the penetrance of the Mediterranean diet into Scotland…” “… albeit in the form of deep-fried pizza.”
  4. 4. Healthy (meets RNI) Unsustainable High GHGe/Land use Sustainable Low GHGe/Land use Unhealthy (doesn’t meet RNI)
  5. 5. Why research on diets?  Two main global problems: 1. Obesity & Non-communicable diseases 2. Climate change Food consumption lies at the basis of both problems  24% of deaths in UK can be attributed to dietary risks (GBD, 2010)  Agriculture accounts for 15-30% of GHG emissions (largest contributor)
  6. 6. Healthy (meets RNI) Unsustainable High GHGe/Land use Sustainable Low GHGe/Land use Unhealthy (doesn’t meet RNI)
  7. 7. Meat reduction – Environmental impacts OMNIVOROUS VEGETARIAN VEGAN Baroni et al. (2007) European Journal of Clinical Nutrition
  8. 8. Meat reduction – Health implications  Reduced meat consumption may benefit the environment  Other research: also health benefits (processed meat)  3.2% risk reduction for diabetes in women  12.2% risk reduction for colorectal cancer in men Aston et al. (2012) BMJ Open
  9. 9. A win – win situation? However:  Animal protein is ‘the best protein you can get’  ‘Bioavailability’ of plant-based protein is lower  It is more difficult to get all your essential (micro) nutrients from plant-based diets
  10. 10. Healthy (meets RNI) Vegetarian diet Meat reduction Vegan diet Unsustainable High GHGe/Land use Sustainable Low GHGe/Land use Unhealthy (doesn’t meet RNI)
  11. 11. It gets more complicated  Most researchers agree: a reduced meat consumption is beneficial  But environmental impact depends on compensation of meat  Vieux et al. (2013): People consuming a healthy diet have higher associated GHG emissions  Fruits and vegetables: low GHG emissions per gram  Expressed per kcal in the same order as animal products!
  12. 12. Healthy (meets RNI) Vegetarian diet High in veg/fruit Vegetarian diet Meat reduction Vegan diet Unsustainable High GHGe/Land use Sustainable Low GHGe/Land use Vegetarian diet High in sugar Unhealthy (doesn’t meet RNI)
  13. 13. Let’s add more complexity  Which environmental indicator do we use?  GHG emissions, land use, water use, phosphorus use, etc.  Current projects focuses on land use  38% of total land is already in use for the production of food and this will increase (Foley, 2011)  Global dietary change will contribute to the increasing demand for land  Cropland vs. grassland
  14. 14. DIETARY CHANGE SCENARIOS Fig. 7 Extent of global agricultural land in scenarios for 2030. Cropland area includes land used also for non-food crops (mainly cotton and rubber), which FAO projects to be roughly 50 Mha in 2030. It also includes land use for cultivation of food-type cr... Stefan Wirsenius , Christian Azar , Göran Berndes How much land is needed for global food production under scenarios of dietary changes and livestock productivity increases in 2030? Agricultural Systems Volume 103, Issue 9 2010 621 - 638
  15. 15. Main challenge  No uniform measure of dietary/nutritional quality  No uniform measure of sustainability  No uniform way of coupling nutritional quality with life cycle assessments of food products  Add to this the social dimensions food security and access, animal welfare, consumer acceptance…  Quest for a healthy food system truly is a ‘wicked’ problem
  16. 16. Future directions  Start with food consumption of Scotland  Combine this with land requirements for food items (either local or FAO)  Based on the preliminary results, I’ll choose how to continue
  17. 17. Future directions  What I’d like to investigate:  We have to move away from traditional yields (ton/ha) to nutritive value per hectare  Is it worthwhile to explore a more spatial approach of land use (impact is local, contrary to GHG emissions)  Is it worthwhile to investigate different socioeconomic groups? Cf. health inequalities vs. impact inequalities
  18. 18. Thanks for your attention! Henri_de_Ruiter