Is a diet low in greenhouse gas emissions a nutritious diet? – Analyses of self-selected diets in the LifeGene study

Climate change is an urgent global issue and the food sector is a major contributor to greenhouse gas emissions (GHGE). Here we study if a diet low in GHGE could be a nutritious diet compared to the Nordic Nutrition Recommendations (NNR).

The environmental impact of foods from Life Cycle Assessment (LCA) data was linked to a food frequency questionnaire (FFQ) filled out by 5,364 participants in the Swedish LifeGene study. Thereafter, we calculated the daily emission of CO₂ equivalents (CO₂e) as well as the intake of selected nutrients associated with vegetables, fruits, meat and dairy products. The CO₂e was divided into quartiles were quartile 1 corresponds to a diet generating the lowest CO₂e, and quartile 4 corresponds to a diet with the highest CO₂e.

The overall diet-related emission was 4.7 kg CO₂e/day and person, corresponding to 1.7 ton CO₂e/year. In general, there were only small differences in nutrient intake between groups of varying levels of CO₂e, regardless if the intake was analyzed as absolute intake, energy percent or as nutrient density. Moreover, adherence to NNR was high for the group with the lowest CO₂e, except for saturated fat where the intake was higher than recommended for all CO₂e groups. On the other hand, only the group with the lowest CO₂e fulfilled recommended intake of fiber. However, none of the CO₂e groups reached the recommended intake of folate and vitamin D.

Here we show that a self-selected diet low in CO₂e provides comparable intake of nutrients as a diet high in in CO₂e.