Each day, the average American throws out 422 grams (nearly 1 pound) of food. That totals more than 150,000 tons nationwide, with diets rich in healthier foods – like fruits and vegetables – wasting the most.
The study, published in PLOS One, didn’t just account for the food scraps leftover from dinner. Instead, researchers examined the relationship between food waste, diet quality, and nutrient waste in the face of agricultural and environmental sustainability in the US.
Estimates suggest almost one-quarter of daily food – or 30 percent of daily calories – goes to waste each day.
It’s not just food that gets chucked out, either. All this waste takes its toll on the environment and farmers, who ultimately waste 4.2 trillion gallons of water, 350 million kilograms (780 million pounds) of pesticides, and 816 million kilograms (1.8 billion pounds) of nitrogen fertilizer to tend to 12 million hectares (30 million acres) of wasted cropland each year.
Oddly enough, healthy diets produce more waste than low-quality diets. Because of their perishable nature, fruits and vegetables tend to get thrown out more often. They also, generally speaking, require less land but use more pesticides and water than other foods, thus contributing to increased waste.
The estimates were compiled using data collected from various US government databases, but it doesn’t come without limitations. Food intake information was gathered from self-reported dietary data that is subject to measurement error. Additionally, estimates included fats and oils leftover from cooking, which some wouldn’t consider waste. Furthermore, the modeling approach was used to reflect US eating habits and may not be indicative of other countries.
Nevertheless, the researchers say it is an issue that demands more attention.
"Eating healthy is important, and brings many benefits, but as we pursue these diets, we must think much more consciously about food waste,” said study co-author Meredith Niles in a statement.
Globally, enough food is wasted each year to feed nearly 2 billion people on an average diet. Previous research suggests a global transition to a “Western diet” (more sugar, sodium, and animal product, among other things) has brought with it issues of health and environmental sustainability. According to the report, countries like Brazil, Germany, Qatar, and Sweden have gone as far as to include measures of sustainability in dietary guidelines.
Efforts to improve diet quality and reduce waste need to go hand-in-hand, say the authors. Those solutions come in the form of increasing consumer knowledge like how to properly prep and store perishables, knowing the difference between “sell by” and “use by” dates, and practicing smart shopper strategies.
As has been said before: once tasted, never wasted, so waste not want not.