[baldfat]

http://www.treehugger.com/green-food/from-lettuce-to-beef-wh...

Answered my own Lettuce -- 15 gallons

Chocolate (One Pound) -- 2847 gallons!!!!!

[Dylan16807]

Where the lettuce has 70 calories and the chocolate has 2500. So about a 5:1 difference in efficiency.