Understanding the relationship between food waste, climate change, and population aging

Producing food and delivering it to people’s tables requires the consumption of large amounts of energy and resources. Unfortunately, around one-third of the food produced around the world goes to waste rather than being consumed. Therefore, minimizing food loss is essential to building a sustainable society.

Based on estimates reported by government agencies, households in Japan generated an astonishing 247 megatons of food waste in 2021, much of which could still be eaten. Thus, there is considerable room for improvement in Japan when it comes to minimizing food waste at home. But the problem is, we don’t know much about what types of food contribute most to food waste, the associated greenhouse gas emissions, and whether certain sectors of the population are more likely to waste food. That’s not true.

Now, a research team led by Associate Professor Yosuke Shigetomi of Ritsumeikan University’s College of Science and Engineering, Asuka Ishigami of Nagasaki University, Associate Professor Andrew Chapman of Kyushu University, and Associate Professor Ying Long of the University of Tokyo has found that Japan is addressing this knowledge gap. I tried.

Through a detailed analysis of food waste in Japanese households that incorporates demographic and dietary trends, they establish important links between the amount and type of food waste, associated emissions, and age. did. Their findings were published in the journal Nature Communications on October 21, 2024.

To conduct their analysis, the researchers collected food consumption and waste statistics from previously published studies. This information allowed the team to determine the ratio of edible to inedible parts for more than 2,000 foods, as well as the physical amount of food waste from households in different food categories. By combining these data with food-related socio-economic statistics, we investigated how age and other factors influence the amount and type of nearly 200 foods that go to waste.

It is worth noting that Dr. Shigetomi highlights Ishigami’s important contribution to this research. “Asuka Ishigami was my former student at Nagasaki University. She graduated as a bachelor in 2022, but she collected all the basic data through her doctoral thesis and provided the initial analysis for this study. I worked hard to do it,” says Dr. Shigetomi. .

One of the most notable findings was that per capita food waste in households appeared to increase significantly with the age of the household head. Households with older adults potentially produced nearly twice as much food waste as households with heads in their 30s, and the difference was quite alarming. The type of food most wasted was also vegetables. Similarly, greenhouse gas emissions associated with food waste also increased with the age of the household head. However, in this case, vegetables, prepared foods, and seafood were the largest contributors.

Taken together, these results highlight how age is directly related to food waste and associated greenhouse gas emissions. “The aging of the population will be one of the hidden but important factors to consider when proposing strategies to reduce food waste generated directly from households,” said Dr. Shigetomi. .

Furthermore, identifying that vegetables and meat are either major or minor sources of food waste, but both are major sources of greenhouse gases, makes it difficult to identify which food categories contribute to these problems. We also highlight the importance of understanding what contributes most to the development of cancer, so that more targeted interventions can be developed. And policy.

“It is essential to pay close attention to the food preferences and lifestyles of different generations, especially as dietary changes toward vegetarianism are desired to combat climate change,” Dr. Shigetomi added.

The results of this study will help develop effective strategies to reduce food waste and increase awareness of the environmental threats it poses. Educational campaigns can go a long way in helping people pay more attention to the food they consume, how it is prepared and stored, and how much of it ends up being wasted.