Sunnuntai 19.8.2018 klo 12:37 - Mikko Nikinmaa
When thinking of the most sustainable diet, it is normally considered that one should turn to fully vegetarian one to feed world's population. If animal products were used at all, they should be from ectotherms like insects and fish. Against this background it came as a surprise that having a small amount of traditional farm animal products in the diet actually reduces the land use needed for obtaining a given amount of energy even as compared to vegetarian diets. This surprising result is caused by the fact that farm animals can utilize feed that is human refuse - something that cannot be included in vegetarian diets. Pigs and cows happily eat the leaves of sugarbeets and turnips, which would just be left to rot and to release the carbon dioxide taken up back to the environment, if strictly vegetarian diet were utilized. This surprising conclusion was reviewd by van Zanten et al. recently (Glob Change Biol. 2018;24:4185–4194). So, the most sustainable diet includes some animal products.