How Much Do We Really Know About “Green” Eating?
Some experts have suggested that avoiding certain foods or food groups might be better for the environment, but new research suggests this may not be the case.
However, the science is young when it comes to evaluating sustainable food systems.
As the science continues to build, we at National Dairy Council know that dairy farmers, the source of the nutrient-rich dairy foods we enjoy, are continuing to innovate and improve the sustainability of their farms, now and for future generations.
Defining sustainable eating plans is a complex task but one that is necessary to help protect our resources and nourish a growing population. Nutrition science and human health, environmental science and planetary health and many other diverse factors must be taken into consideration together. The 2015 Dietary Guidelines Advisory Committee noted that all of the recommended Dietary Guidelines for Americans Healthy Eating Patterns – Healthy U.S., Mediterranean and Vegetarian (which is ovo-lacto or contains eggs and milk) – represent healthy and sustainable choices compared to current U.S. consumption habits.
A new review by a group of French scientists used consumption data and found some eating plans could be considered environmentally sustainable without avoiding animal foods or entire food categories. Researchers reviewed 10 studies that used dietary survey data to assess the sustainability of eating plans by investigating both the environmental impact and nutritional quality of the diet.
In the past, these researchers have used statistical modelling to simulate which dietary changes are needed to optimize nutritional quality, health, environmental impact, affordability and social/cultural acceptability. However, some theoretical changes suggested by this type of research may not be realistic for people to implement in their daily lives. In this review they analyzed real food choices rather than theoretical dietary patterns for a better consideration of cultural acceptability.
The new review by French scientists also highlighted key learnings that can guide evolving research and conversations about sustainable eating plans and nutrition, including the following:
- Eating less meat is associated with fewer greenhouse gas emissions (GHGE), but what replaces the calories from meat in the diet is equally important, both environmentally and nutritionally. Some of the reviewed studies showed that certain diets were more sustainable in this regard when they included meat.
- Reducing calorie consumption is a principle factor in reducing GHGE. Eating only the amount of food your body actually needs can have a positive effect on the environment. A study included in this review showed that “just reducing food consumption to match the estimated energy requirements of each person may lead to a 10 percent decrease in GHGEs without the need to modify their habitual food patterns.”
- Different aspects of sustainability must be considered and may not be compatible. For example, diets with higher nutritional quality (i.e., more fruits, vegetables, whole grains) did not necessarily have the lowest environmental impact. It’s important to find a balance between the nutrition and health needs of people and the stewardship of the planet’s resources.
- Only a few studies properly assessed the nutritional adequacy of diets by considering a large number of nutrients. Only partially assessing nutritional quality compromises the accuracy of the overall sustainability assessment.
Overall, this review emphasizes the importance of taking a holistic approach when evaluating nutrition and sustainability. Nutrient content, health, environmental impacts, affordability and cultural acceptance should be examined together. There is also a need for better quality data on food prices so more studies can include the affordability dimension of sustainability. Future research may also examine cultural acceptability of sustainability by considering real food choices rather than theoretical eating patterns.
Working together, farmers, health and wellness professionals, nutrition and environmental scientists and others, can provide solutions to help nourish a growing world population in a sustainable way and complement nutrition recommendations. Dairy farmers have always been stewards of the land and continuously work to improve their management of resources and honor their commitment to provide nutrient-rich milk to people in the most sustainable way possible. This summer, we will be announcing our 2017 Dairy Sustainability Award winners, including dairy farms and operations that have made improvements to benefit the environment, their bottom lines, and the communities in which they work and live.