GHGE Differences Between Product Groups: Animal Versus Plant Protein
The results presented in the previous section confirm a correlation between the level of GHGEs and most individual macronutrients. They show that animal protein has the strongest positive correlation and plant protein has a significant negative correlation. Considering product groups (Fig. 1), all animal products together have significantly higher GHGEs than plant-based food groups (p < 0.001). The difference is a factor of three or more: 651 g CO2eq/100 g for the animal products versus 218 g CO2eq/100 g for cereal products. Because the log10 transformation results in linear correlations, we can conclude that products with GHGE values in the order of 2.0 can be consumed by a factor of 10 more than products with values of 3.0 or higher, without increasing the total climate impact (e.g., 100 g of mushrooms versus 10 g of cheese). We can conclude that the level of GHGEs is generally lower in plant-based products than in animal-based products - in particular in red and processed meat. Plant protein content is therefore a useful nutritional indicator of low GHGE product groups. The opposite holds for saturated fatty acids as a useful nutritional indicator of high GHGE animal product groups.