Americans are concerned about wasting food — yet they just can’t seem to stop throwing it out.

Some 76% of households say they throw away leftovers at least once a month, while 53% throw them away every week, according to a survey released Wednesday of 1,000 consumers by market research firm TNS Global on behalf of the American Chemistry Council. (The latter is a trade organization for the U.S. plastics industry and so has a vested interest in people using its products to preserve food.) Despite throwing out food, 70% of people say they are bothered by the amount of food wasted in the U.S. Respondents estimated wasting $640 in household food each year — but U.S. government figures estimate people waste closer to $900.

Previous reports suggest even more people throw out unwanted or expired food. Over 90% of Americans may be prematurely tossing food because they misinterpret expiration dates, according to a separate 2013 study released by Harvard Law School’s Food Law and Policy Clinic and the Natural Resources Defense Council, or NRDC, a nonprofit environmental action group. Phrases like “sell by,” “use by,” and “best before” are poorly regulated and often misinterpreted, the report found: “It is time for a well-intended but wildly ineffective food date labeling system to get a makeover.”

Faulty expiration-date rules are confusing at best and, according to another report released this month by Johns Hopkins Bloomberg School of Public Health, the desire to only eat the freshest food and food safety concerns are the two main reasons for throwing it out. “Sell by” dates are actually for stores to know how much shelf life products have. They are not meant to indicate the food is bad. “Best before” and “use by” dates are for consumers, but they are manufacturers’ estimates as to when food reaches its peak. For most food, manufacturers are free to determine the shelf life for their own products.

Read: Why you should stop buying bottled water

All the wasted food adds up: As much as 40% of food goes uneaten in the U.S., according to the government. Americans trash $165 billion in wasted food every year, a separate analysis by the NRDC found. In fact, one study estimates, just 15% of all this wasted food would be enough to feed more than 25 million Americans every year. France recently tried to address its own food waste problem by passing a law to ban supermarkets from throwing out food. (The United Nations’s Food and Agriculture Organization estimates that one-third of global food production is either wasted or goes uneaten.)

Americans are wasting substantial quantities of food, whether they care to admit it or not, says Roni Neff, director of the Food System Sustainability & Public Health Program at the Center for a Livable Future at the Johns Hopkins Bloomberg School of Public Health in Baltimore, and assistant professor in the Bloomberg School’s Department of Environmental Health Sciences. “It happens throughout the food chain, including both a lot of waste by consumers, and a lot on our behalf, when businesses think we won’t buy imperfect food. The root causes are complex.”

Most people don’t realize that trashing food is bad for the environment. Only 15% of respondents in the American Chemistry Council study made the link between food waste and adverse impacts on the environment. Some 160 billion pounds of food are thrown away in the U.S. annually, making food waste the single largest contributor of solid waste in landfills, according to the Harvard Law School and NRDC study. “People from all walks of life and around the globe understand that wasted food is a critical issue,” says Steve Russell, vice president of plastics at the American Chemistry Council.

Read: Low-calorie food and drinks drive supermarket sales