When one of Ted Jaenicke’s doctoral candidates approached him about quantifying household food waste, his first thought was that it could be nearly impossible.
“It’s just not something that’s measured, food waste,” said Jaenicke, a professor of agricultural economics at Penn State. “It never shows up in any data set at all.”
Using survey data from the U.S. Department of Agriculture and a nutritional science formula, Jaenicke and his student, Yang Yu, were able to calculate the difference between what households were buying and how much food they actually needed to maintain each person’s body weight.
The result: about 30 percent of food is wasted.
They also determined the average home spends more than $1,800 per year on food that’s never eaten.
Jaenicke said they found a wide range of waste across households.
“The least-wasting household is just under nine percent of food waste and the most wasteful households can go above 80 percent,” he said.
He added a notable finding is that wealthier households and those with a healthier diet tend to waste more food.
Jaenicke said the study identifies what’s happening but doesn’t answer why people waste food. He said he hopes it will inspire further behavioral research into ways to reduce food waste without unintended consequences, such as people eating less fresh, perishable fruits and vegetables.
Jaenicke said reducing food waste is important because it creates methane in landfills, contributing to climate change.
According to the U.N. Food and Agriculture Organization, if global food waste were a country it would be the third-largest emitter of greenhouse gases, behind China and the U.S.