Household food waste is a major factor in global food loss, waste, and greenhouse gas emissions. However, details about the types of food wasted and the demographics of those wasting it remain unclear. Recently, researchers examined how food waste correlates with food type and various socioeconomic and demographic characteristics. Their results aim to help formulate effective strategies to reduce food waste in Japan and other aging developed nations.
Household food waste significantly contributes to global food loss and greenhouse gas emissions, yet little information exists on what specific types of food are often wasted and by whom. A new study from Japan has explored the connections between food waste, the types of food involved, and related socioeconomic and demographic factors. These insights will assist in formulating effective approaches to reduce food waste, particularly in Japan and other developed countries grappling with aging populations.
The production of food is a foundational aspect of human civilization and has led to substantial changes in the world’s landscapes. The process of food production and distribution requires immense energy and resources. Alarmingly, approximately one-third of all food produced worldwide goes uneaten and is discarded. To foster sustainable communities, it is crucial to reduce food waste.
In Japan, governmental estimates reveal that households generated an astonishing 2.47 megatons of food waste in 2021, much of which was likely still safe to eat. This indicates a significant opportunity for Japan to enhance its efforts in reducing household food waste. However, there is a lack of detailed information about which food types contribute most to this waste, the greenhouse gas emissions associated with them, and whether certain demographic groups are more likely to waste food.
To shed light on this issue, a research team led by Associate Professor Yosuke Shigetomi from Ritsumeikan University’s College of Science and Engineering, in collaboration with Ms. Asuka Ishigami from Nagasaki University, Associate Professor Andrew Chapman from Kyushu University, and Associate Professor Yin Long from The University of Tokyo, embarked on this investigation. By analyzing food waste in Japanese households alongside demographic and dietary trends, they identified key relationships between the quantity and type of food waste generated and the greenhouse gas emissions associated. Their findings were published in Nature Communications on October 21, 2024.
For their analysis, the researchers compiled food consumption and waste data from existing surveys. This allowed them to assess the ratios of edible to inedible parts across more than 2,000 food items, as well as to quantify food waste across different categories. By merging this data with socioeconomic factors related to food, they examined how age and other elements influenced the waste of around 200 food items.
Dr. Shigetomi emphasized the vital role played by Ms. Asuka Ishigami in this research. “Ms. Ishigami, who was my student at Nagasaki University, graduated in 2022. She diligently gathered the essential data and conducted the preliminary analysis for this study as part of her bachelor’s dissertation,” noted Dr. Shigetomi.
One of the key insights revealed that food waste per person in households tends to rise significantly with the age of the head of the household. The findings showed that elderly homes might generate almost double the food waste compared to those where the head is in their 30s. Vegetables were identified as the most frequently wasted food type. Correspondingly, greenhouse gas emissions linked to food waste also increased with the age of the household’s head, particularly from vegetables, ready-made meals, and seafood.
Overall, these findings underline a potential direct connection between aging and food waste, along with the associated greenhouse gas emissions. “The aging population may be an underlying yet critical factor in developing household food waste reduction strategies,” remarked Dr. Shigetomi. Furthermore, recognizing vegetables and meats as significant contributors to food waste and greenhouse gas emissions highlights the need to understand which food categories are the primary offenders. This understanding aids in creating more effective targeted interventions and policies. “It’s essential to consider the dietary habits and lifestyles of different generations, especially as dietary shifts towards vegetarianism emerge as a strategy to combat climate change,” Dr. Shigetomi asserted.
This study’s outcomes will inform the creation of effective strategies for curbing food waste and raising awareness of its environmental impact. Educational initiatives may significantly encourage individuals to be more conscious about their food consumption patterns, cooking methods, storage practices, and the amount of food they discard.
