Assume that an animal consumes 200 ml of O2 in the course of metabolizing 250 mg of food. Determine the probable kind of food the animal has metabolized. How much heat has been produced?

I determined the food type by dividing 200 by 250 to get 0.8 ml O2/mg, which is close to the table value given as 0.84. However, I'm not sure how to calculate the heat produced. This info is given for the food type I chose: cal/mg=4.2, cal/ml O2=5, cal/ml CO2=5. I know it can be calculated with determining O2 consumption, but I don't know how. Please help.