Back in 2011, the Food and Agriculture Organization of the United Nations released a much-quoted statement suggesting that up to one-third of all food produced for human consumption is wasted instead of ending up in our bellies. Sadly, that estimate may be too conservative.

An updated study in PLOS ONE—which took a closer look at consumer behavior, in addition to the supply chain—found that food waste could be twice as high as previously thought, reaching a staggering 527 calories per day per person. The report linked food waste to wealth, finding that when a person’s spending (in total, not just on food) reaches about $6.70 per day, food waste begins to creep upward.

On top of this, the rapid shift in food supply that was required to switch from serving restaurants to serving the retail food business during the COVID-19 pandemic hasn’t been easy and has further increased food waste. Farmers typically plan for their sales outlets months in advance, so when their markets (restaurants, etc.) close and farmers cannot keep all their workers, some crops end up rotting in the fields. More home cooking can also lead to a greater tonnage of food scraps going to landfills.

The PLOS ONE findings suggest that reducing waste globally requires reducing high waste levels in wealthier countries. That will mean taking steps to improve the supply chain and teaching people better kitchen habits, like menu planning, so they buy only what they are going to use.