Climate change is an urgent global issue and the food sector is a major contributor to greenhouse gas emissions (GHGE).
The primary aim was to study diet-related GHGE and its relation to nutrient intake and iron status in the
Swedish cohort study LifeGene. The environmental impact of foods from Life Cycle Assessment (LCA) data was linked to a web-based food frequency questionnaire (FFQ) filled out by 5364 participants. 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 and analyzed hemoglobin in blood.
The overall diet-related emission was 4.7 kg CO₂e/day, corresponding to 1.7 ton CO₂e/year, and the emission was lower for women, 4.4 kg CO₂e/day, than for men, 5.3 kg CO₂e/day. In general, there were only small differences in nutrient intake between quartiles of CO₂e, regardless if the intake was analyzed as absolute intake, energy percent or as nutrient density.
Beef and ground meat was eaten 2.1 times per week among women and 3.5 per week among men. Beef is a major contributor of CO₂e and a rich source of iron, a mineral of particular importance for women in child-bearing ages, but there was no correlation between CO₂e and dietary iron for women.
Substituting a theoretical serving of 100 grams of beef per week for tofu corresponds to a 97% reduction in CO₂e per serving or a 15% reduction of the total kg CO₂e per day for women and 13% for men.
This study showed that there are large differences in diet-related greenhouse gas emissions. Men and older people tend to have food habits that generate higher emissions than women and younger people. Beef, pork and dairy products generate the most greenhouse gas emissions while plant-based foods such as roots, beans, grains, vegetables and fruit generates the least. But it is also important to think about eating seasonally, as fresh fruit can have a high climate impact if transported by air from the other side of the globe. “Overall it is possible to eat both climate friendly and nutritious” says Katarina Bälter.
- Sjors C, Hedenus F, Sjolander A, Tillander A, Balter K. Adherence to dietary recommendations for Swedish adults across categories of greenhouse gas emissions from food. Public Health Nutr 2017;20:3381-93.
- Balter K, Sjors C, Sjolander A, Gardner C, Hedenus F, Tillander A. Is a diet low in greenhouse gas emissions a nutritious diet? – Analyses of self-selected diets in the LifeGene study. Arch Public Health 2017;75:17.
- Sjors C, Raposo SE, Sjolander A, Balter O, Hedenus F, Balter K. Diet-related greenhouse gas emissions assessed by a food frequency questionnaire and validated using 7-day weighed food records. Environ Health 2016;15:15