This post originally appeared on Forbes.com.

Thanksgiving is time for celebration of family, football, and friends, sandwiched between platters of turkey, stuffing, and pumpkin pie. But when you head out to pick up those last minute ingredients for your Thanksgiving feast, you may want to consider just how much food won’t get eaten at your table.

Recent analysis from the World Resources Institute finds that nearly one-quarter of all food (measured by calorie) produced for people globally is lost due to spoilage or waste. In the U.S., the number is even higher, with a whopping 42 percent of all calories not reaching people’s mouths. Of that, about 20 percent of meat is lost or wasted. That means come Thanksgiving Day, of the approximately 46 million turkeys likely to be purchased, over 9 million will go uneaten.

Highlighting this issue can help you to think about ways you can reduce food waste, while helping to ensure that we meet the world’s growing food demand.

Here are three things you should know about food loss and waste:

1. Our Food Needs Are About to Skyrocket

One of the questions the world faces is how to feed a population that’s on pace to exceed 9 billion people by 2050 in a way that supports farmers and promotes economic growth, and, at the same time, reduces pressure on the environment.

According to WRI, the world will need 69 percent more calories per year in order to feed the global population in 2050. The good news is that cutting current food loss and waste in half would shrink this food gap by 20 percent—that would help a lot more people get the nutrition they need.

2. Food Waste Has Real Economic Impacts

Food waste is costly for consumers, businesses, and countries. On average, Americans throw away 20 pounds of food each month, costing an average of $1,600 per year for a family of four.

Waste occurs outside the home, too. American diners typically don’t finish 17 percent of the food they order in restaurants and leave 55 percent of these leftovers behind, rather than taking unfinished portions home to eat later. That’s a lot of unused doggie bags.

Meanwhile, food waste is a global issue. Worldwide, the economic cost of food waste in 2007 totaled about $750 billion.

3. Reducing Food Waste Brings Environmental Benefits

Improving the efficiency of food production and consumption will help people and the planet. Agriculture is a major contributor to global greenhouse gas emissions—which is the main driver of man-made global warming–with nitrous oxide from fertilizer and carbon dioxide from plowing fields accounting for roughly 10 percent of global emissions.

One unexpected benefit of reducing food loss and waste would be to reduce global greenhouse gas emissions. An FAO report from September found that food loss and waste are responsible for about 3.3 billion metric tons of greenhouse gas emissions every year. That’s about one-half of the total U.S. greenhouse gas emissions (based on 2011 levels).

If we better utilize food that is food already grown, we can also help protect land and sensitive ecosystems. For example, by decreasing demand for additional food production, we can reduce the need to convert land for agriculture and livestock; cut down on fertilizer use; and use less energy for producing, processing, transporting, and storing food. Plus, diverting food loss and waste from landfills prevents methane emissions from rotting food.

Awareness Is Growing and Solutions are Possible

Fortunately, businesses are starting to recognize the importance and opportunity of reducing food loss and waste. For instance, the British supermarket Tesco, one of the world’s largest food retailers, recently announced that it generated almost 30,000 metric tons of food waste in the first six months of 2013. The company has said it wants to lead the way in reducing food waste, including promoting smaller bags of produce.

Similarly, the supermarket chain Stop & Shop saved an estimated $100 million annually after an analysis of waste and customer satisfaction in their perishables department, according to the Natural Resources Defense Council.

To support businesses and governments measure and manage food loss, the WRI recently announced that it is working with other leading organizations to develop a new “Food Loss and Waste Protocol.” The goal is to create a consistent global standard for countries and companies to measure and monitor food loss and waste within their boundaries and across their value chains.

Of course, there are simple steps for people to take as well. These include redistributing uneaten food through food donations; keeping food in coolers when refrigeration is unavailable; using hermetically sealed bags to store crops; using plastic crates instead of bags to protect soft fruits and vegetables; making food date labels simpler and less confusing; and reducing portion sizes at restaurants and cafeterias.

Through these steps, people can help reduce food loss and waste and make an important contribution to ensure that more people have enough food to meet their needs.

So, enjoy your Thanksgiving feast, but also keep in mind how much food is lost and wasted, in your home and around the world, every day. By reducing food loss and waste, we can help ensure there’s enough food to go around for all people.