And while that might sound like a lot, it's just 1.5 burgers per week. Plus, you might improve your health, too.

If you're grilling up burgers on the regular this summer, you might want to reconsider your protein choice. According to "Creating a Sustainable Food Future," a new report from the World Resources Institute, Americans need to reduce their average consumption of beef by around 40%, and Europeans by 22%, in order for the world to continue to be able to feed roughly 10 billion people (the population predicted to live on this planet in 2050). And that comes out roughly to about a burger and half each week, as long as everyone on the planet is in it together.

Surprise! The pictured "burger" above is made with a mushroom patty (Get the recipe for Vegetarian All-American Portobello Burgers).

The Problem

Demand for food is predicted to increase by more than 50% by 2050. With an increasing population and rising incomes (and needs), it will become harder to feed everyone and avoid malnutrition.

What's more, meat and dairy are in particular demand (hence the idea of cutting out a burger and a half), and demand for those animal-based foods projected to increase by 70%. The global demand for beef, sheep and goat meat will increase even further, by about 88%. The report also says that farmers will need to supply 56% more crop calories in 2050 than they had to back in 2010, which means they'll need substantial amounts of land, an area that's nearly twice the size of India.

Why Meat?

You might be thinking, "Why meat?" and it's because it takes much more land, water and resources to produce meat than to produce plant-based proteins, like legumes and pulses. Farming meat requires more than 20 times more land, which produces more than 20 times more greenhouse gas emissions per gram of protein delivered, as opposed to pulses, according to the report. Pulses include dry beans and peas, chickpeas and lentils. Cows develop and reproduce slower than pigs and poultry, so they're going to require more food, land, water and other resources.

What's more, beef itself is responsible for 41% of livestock greenhouse gas emissions, and livestock produces 14.5% of total global emissions, as explained by the Food and Agriculture Organization of the United Nations. Plus, the report says, beef provides about 3% of the calories in the average American diet, but it requires about 43% of U.S. land. Crazy, right?

How to Cut Back

If you're cutting back a burger and a half a week, that's about 6 ounces, as the average burger patty is 4 ounces. The problem is that meat lovers may not know how best to cut back or what to eat instead to still feel satisfied.

Going plant-based, even part-time, would be great. Swapping beef for chicken and pork on occasion will also benefit climate and land use.

Luckily, there are several plant alternatives on the market, for burgers, hot dogs and meat slices, and you can still grill them or cook them as you would with beef. Common veggie burger and meat substitute ingredients are beans, mushrooms, tofu, quinoa and legumes. You can then always amp up the flavor with tasty sauces, marinades and toppings, so you won't miss meat one bit or feel deprived.

If you're don't think you're ready to go full plant-based (or if you've tried faux-meat options and don't like them), then you can also make your own burger patties and swap out half the amount of ground beef for a vegetarian substitute, like mushrooms, beans or quinoa, which will still provide a nice texture and flavor. This type of patty is often referred to as a blended burger. If you're trying to cut back on the beef you'd eat, for example, in tacos or lasagna , you can also try including mushrooms to round out a smaller amount of beef, or use turkey, chicken or fish instead if you're not ready to go full-on veg.

And, let's not forget, eating less meat and more plants can also improve your health. In particular, eating less red meat could benefit your health, as previous research has shown that eating red meat might increase the risk of diabetes, heart disease and even some cancers.