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Why Is One-Third of Our Food Wasted Worldwide? Study Examines Causes of Food Waste and Potential Solutions

By Amy Quinton on October 1, 2019 in Food & Agriculture

Quick Summary

  • An estimated 20 percent of food waste is on farms, in storage or transit in industrialized countries
  • In less-developed countries, an estimated 30 percent is lost from inadequate storage, drying or cooling and transportation
  • Consumer waste often a result of social and cultural factors

Nearly one-third of all the food that is produced in the world never gets eaten. By some estimates, we waste 30 million tons of food in the U.S. and 1.3 billion metric tons worldwide every year. All this waste has huge economic, environmental and social costs.

“When people hear those numbers, they think there’s an easy solution, that we should just stop wasting food,” said Ned Spang, an assistant professor in the Department of Food Science and Technology at the University of California, Davis. “It’s not that easy. We’re just starting to scratch the surface in really understanding the dynamics of this complicated problem.”

Spang led a team of researchers examining food loss and waste in a new study published in the journal Annual Reviews of Environment and Resources. The comprehensive review finds that large systemic factors drive food waste. The study points to the need to look at structural, cultural and social factors rather than only focusing on actions by individual producers and consumers.

Loss in fields and after harvest

Some drivers of food waste include food left in fields due to weather, pests and disease. Farmers can’t afford to harvest food if the market price is too low or labor costs too high. A significant portion of food gets wasted if it doesn’t meet market-based quality standards such as a fruit or vegetable’s color, shape, size and level of ripeness.

“People see food left in the field after harvest and think farmers are being wasteful,” said Spang. “It’s an unfair characterization because it really does not make sense to harvest a crop if it’s not going to be eaten.”

In developed countries, an estimated 20 percent of food is wasted on the farm from improper or inadequate drying, storage, packaging and transportation. In less-developed countries, an estimated 30 percent of food is wasted because growers often can’t afford the energy costs of drying, adequate storage or refrigerated transportation. Inadequate road infrastructure can also lead to higher levels of spoilage.

Retail and consumer waste

Grocery stores also contribute to food waste by encouraging consumers to buy more than they need, overstocking shelves, inaccurately predicting shelf life or damaging products. Restaurants and food services waste food by mismanaging inventory, poor menu choices or oversized portions.

Most studies on consumer food waste focus on individual actions, including over-purchasing, instead of social and cultural factors, said Spang.  

“You can’t just look at a household’s waste and blame the family,” said Spang. “Food might go to waste because people are too busy to cook and misjudge the amount of food they need. They may live in rural areas and have to stock up and buy too much food rather than frequently driving long distances.” Spang said in many cultures, running out of food is socially unacceptable, so better to have too much food than too little.

Solutions for food waste

Solutions to prevent food waste can be just as complex as the causes. Relaxing cosmetic quality standards for fruits and vegetables could prevent waste on farms. It would require policy changes and changes in consumer behavior. Training and education about packaging, storage and transportation could help prevent waste after harvest but would require significant investment in developing countries.

Studies have shown that smaller portions in restaurants and the food service industry reduce food waste. Awareness campaigns for consumers about food waste show results, but the programs need to address how people relate to their food in everyday life.

“The good news is that the issue is receiving increasing attention from government, industry and academia at the global, national and local scales,” said Spang. “Despite its complexity, there are many established and emerging opportunities for targeted solutions to reduce, recover and recycle food waste across the food supply chain.”

Learn more about the study and how reducing food waste can help feed a growing population here or listen to Episode 3, “You’ve Come a Long Way Baby Carrot” of Unfold, a UC Davis podcast.

Media contact(s)

Amy Quinton, News and Media Relations, 530-752-9843, cell 530-601-8077, amquinton@ucdavis.edu

Ned Spang, Food Science and Technology, 530-754-5447, esspang@ucdavis.edu

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