Variability in food caloric value

New Years Day I am having dinner with a good Jarrett at a chain restaurant eating one of their health conscious salads.  We were commenting on how the volume of the salad changed every time we went there to eat.  That led to the discussion of how many calories were actually in the salad vs. how many the restaurant advertised in the menu.  One thing led to another, bets were made, and now I am looking for access to a calorimeter which will allow us to measure the caloric content of said salad.  Now being in Boston and at MIT, you would think that it would not be hard to find such a machine.  It is now the 10th of January, and I am still looking for the calorimeter.  BTW, if you happen to have one just tucked away in the corner of your basement or your laboratory, drop me a line.