The link between what we eat and its impact on our health and the environment has been well established. While many studies have focused on the impacts of diets in broad terms at the level of food groups, a new study led by researchers at the University of Tokyo takes a more nuanced approach by looking at the impacts of diets at the dish level. This approach takes into account people’s different connections with their diets around the world, which have strong cultural associations. The study found that mixed diets can offer good health and environmental outcomes as they provide a larger diversity of dishes that can meet both nutritional requirements and have low carbon footprints.
The lead author of the study, Associate Professor Yin Long, explains that the research identified trade-offs in terms of nutrition, carbon footprint, and price for individual dishes with multiple ingredients. The study focused on analyzing 45 popular dishes in Japan that consist of multiple ingredients and have different cooking times. They found that while diets based on dishes with a greater proportion of plant-based ingredients tend to have lower carbon footprints, they sometimes fail to meet daily requirements for some nutrients. In contrast, mixed diets strike a balance between good nutritional outcomes and low carbon footprints due to the larger combinations of dishes they afford.
The researchers stress that impact analyses based on food groups and dishes are not mutually exclusive but highly complementary. While approaches relying on food groups can reveal broadly what sustainable diets can look like and how to achieve them at the production level, dish-based approaches can inform better the day-to-day organization of food consumption at the national and local levels. This approach takes into consideration cultural preferences, cooking methods, ingredient availability, and local environmental conditions that influence dietary habits in different countries and local contexts.
Professor Alexandros Gasparatos, another author of the study, emphasizes the importance of dietary choices for both human health and the environment. Unhealthy dietary habits have been associated with the increased prevalence of obesity, diabetes, and various types of cancers, while food production can have severe environmental impacts such as land use, carbon emissions, water pollution, and overconsumption. The engagement with this research has reaffirmed the belief in the benefits of mixed diets for Gasparatos and has helped identify items and dishes that may need to be consumed in moderation. The study was funded by the Leading Initiative for Excellent Young Researchers (LEADER) Program of 2022 and financially supported by the Asahi Group Foundation.
