Healthy foods have less environmental impact than unhealthy foods
We’ll need to change what we eat to have a livable planet
Nine of the top 15 risk factors for illness globally arise from poor quality diets. Diseases linked to poor diets account for 40 percent of deaths globally. Food production creates about 30 percent of greenhouse gasses and 70 percent of water withdrawals from streams and the ground, among other adverse environmental effects. Could current diets be feasibly altered to produce better health outcomes and reduce the adverse environmental effects of food production? Researchers identified 16 food groups that are linked to better health outcomes and calculated the health and environmental impacts of one additional serving per day of the each food group.
Happily, food groups that predicted large reductions in risk for one disease outcome tended to predict large reductions in risk for other disease outcomes. Similarly, foods that had lower adverse effects for one environmental impact tended to have lower adverse impacts for others. Foods associated with improved health (whole grains, fruits, vegetables, legumes, nuts, olive oil) had among the lowest environmental impacts. Fish had lower environmental impacts than red and processed meat. A transition from current diets to healthier diets would lead to less disease and less environmental impact.
Food production is a major driver of global climate change, biodiversity loss, freshwater use, excess nitrogen and phosphorus use, and land-use change. The EAT-Lancet Commission involved scientists in health, agriculture, political science, and other disciplines from 16 countries. They investigated the possibility of sustainably producing sufficient healthy food to feed 10 billion people by the year 2050. All this while operating within a safe space that reduces greenhouse gas emissions, maintains biodiversity, and keeps pollution within acceptable levels.
Modeling exercises suggest that this future is possible, albeit with an unprecedented level of global cooperation and resourcefulness. In line with the above, healthy food groups have smaller environmental footprints than less healthy foods. A healthy reference diet featured vegetables, fruits, legumes, whole grains, nuts, seeds, and plant oils. Less healthy foods with large environmental impacts include red meat, processed meat, poultry, refined grains, and starchy vegetables. With wide adoption of the reference diet, sustainable production of healthy foods would increase, while that of less healthy foods would decrease. Greatly reducing meat production, especially red meat, would have the largest positive impact on sustainable food production given widespread adoption of the reference (or similar) diet.
The 2019 EAT-Lancet report called for country-specific studies to assess the possibility of achieving greenhouse gas reductions called for in the 2018 Intergovernmental Panel on Climate Change report. Researchers in the Netherlands did just that for their country. They established three targets to reduce greenhouse gas remissions to 1.1. 1.5, and 2.5 kg CO2 equivalent per person per day and follow the existing average Dutch diet as closely as possible. The current average greenhouse gas emissions in the Netherlands from food production, distribution, consumption, etc. is 4.21 kg CO2 equivalent per person per day. Meeting the even less aggressive targets (2.5, 2.1 kg) would require substantial shifts in food production. Foods with large increases in production would include dark green vegetables, other vegetables, fish and shellfish, dry beans, tree nuts, and soy products. Foods with large decreases would include cheese, liquid dairy, butter, beef and lamb, pork, and snacks. Meeting the most aggressive CO2 target would require greater shifts in food production and would not align well with current Dutch food preferences. Achieving sustainable food production in the Netherlands will be challenging.
Germany has adopted Sustainable Development Goal (SDG) 12: Sustainable production and consumption. More specifically, achieving the SDG 12.3 target of reducing food waste by half. A recent study suggests that this approach misses the mark. Researchers mapped the German food supply chain and its resource footprints following the Food and Agriculture Biomass Input-Output Model. Footprints included cropland, biomass, and blue (clean) water. In addition to the existing average German dietary pattern, other feasible diet scenarios included 1) the German guideline diet, 2) a sustainable diet (based on the EAT Lancet Commission), and 3) a vegetarian diet.
Model results showed that the sustainable diet would lead to smaller cropland and biomass footprints (54 and 43 percent lower) but a slightly larger blue water footprint (7 percent larger) compared to the current German diet. The declines in the three footprints would be 3-5 times larger than those achieved with reduced food waste assuming no change in diet. Reductions in both cropland and biomass footprints would arise largely from reductions in animal products, such as dairy and meat. Increases in fruit and vegetable production in the three feasible diet scenarios would lead to modest increases in the blue water footprint. Reducing food waste is more effective at reducing the blue water footprint than reducing the other footprints. Pursuing alternative diets might work at cross-purposes with the target of reducing food waste by one-half. In any event, pursuing a sustainable or vegetarian alternative diet would likely lead to substantial reductions of cropland and biomass footprints.