As a biased omnivore, it would probably be a bit more useful to compare the calorie content of 1 lb of beef vs 1 lb of vegetables. I understand the point you're getting at but the bias might be a little bit too strong there.
shows 10.19 litres/calorie beef vs 1.34 liters/calorie vegetables. Which is an even greater distance than the gallons per pound I mentioned. This obvioulsy can't be right. I will argue that theory wise it makes sense that a plant based diet would use less than a diet consisting of eating animals that ate the plant based diet. The animals are expending energy! You could argue that we can feed animals lower water usage plants than we can feed humans, but does that really make a healthy animal for human consumption?
That said, there are other negatives associated with beef production and consumption :).
Soybeans have about 2000 calories / lb, based on the number Google gives me of 446 calories / 100g. A random website claims soybeans take 200 gallons of water to produce 1 lb, which comes out to about 10 calories / gallon.
That said, you can make huge gains just by switching from beef to pork or chicken. Pork uses about half the resources of beef, per pound, and chicken about a third. Eat your beefs for special occasions, eat chicken and pork if you want every-day meats.
http://www.waterfootprint.org/?page=files/Animal-products
shows 10.19 litres/calorie beef vs 1.34 liters/calorie vegetables. Which is an even greater distance than the gallons per pound I mentioned. This obvioulsy can't be right. I will argue that theory wise it makes sense that a plant based diet would use less than a diet consisting of eating animals that ate the plant based diet. The animals are expending energy! You could argue that we can feed animals lower water usage plants than we can feed humans, but does that really make a healthy animal for human consumption?
That said, there are other negatives associated with beef production and consumption :).
Also - not all calories are created equal.