WEDNESDAY, Feb. 12, 2020 (HealthDay News) -- Much more food is wasted worldwide than commonly thought, a new study shows.

In 2005, the Food and Agriculture Organization of the United Nations (FAO) estimated that one-third of all food available for human consumption was wasted.

This figure has been used to show the extent of food waste worldwide, but it considers supply alone and not consumer behavior.

The new study investigated if and how consumer wealth (affluence) may affect food waste. Researchers created a dataset that provides estimates of global and country-by-country waste.

Once consumer spending reaches about $6.70 a day per person, they found, waste grows -- initially increasing quickly with rising wealth, and then at much slower rates at higher levels of wealth.

The study also suggests that FAO's estimates may be too low. The FAO estimated food waste to be 214 Kcal/day per person in 2015, but the new model estimated food waste as 527 Kcal/day per person in that year. (Kcal is the energy it takes to raise the temperature of 1 kilogram of water by 1 degree Celsius.)

The study was published Feb. 12 in the journal PLoS One.

"Novel research using energy requirement and consumer affluence data shows that consumers waste more than twice as much food as is commonly believed," the authors wrote, adding that the findings provide "a globally comparable base" for measuring progress in reducing waste.

They also "suggests a threshold level of consumer affluence around which to launch intervention policies to prevent food waste from becoming a big problem," the authors wrote.

Monika van den Bos Verma of Wageningen University and Research in The Netherlands led the study.

The findings suggest that reducing waste globally requires reducing high waste levels in high income countries, and preventing waste levels from rising rapidly in lower-middle income nations where wealth is increasing.

More information

The U.S. Department of Agriculture has more on food waste and loss.