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Every year, Americans eat 200 pounds of meat each-equal to a little more than two McDonald’s Quarter Pounders, per person, per day. That’s about twice the global average; but now the rest of the globe (led by China) is catching up fast.

Except it’s highly unlikely that Americans will be able to maintain anything close to current levels of carnivory by 2050, or that people in China, India, and other developing nations will be able to enjoy current US-style diets. There are a number of ways to reach this conclusion-for example, meat production is a massive generator of climate-changing gases-but here’s one that seems pretty fundamental: There just isn’t enough water.

In a new report-which makes bracing reading in this season of widespread drought, severe crop losses, and high food prices-the Stockholm International Water Institute does the math (hat tip to Grist’s Philip Bump):

 The analysis showed that there will not be enough water available on current croplands to produce food for the expected population in 2050 if we follow current trends and changes towards diets common in Western nations.