Assume you drank 240mL of coffee at 80degrees C and that this amount was cooled by your body to the normal 37 degrees C. How many calories were supplied to your body? Assume that the coffee is essentially hot water with a density of 1.0g/mL
240 mL of coffee has a mass of 240 g.
Heat transfer to the body is the heat lost by the coffee,
M* C * (delta T)
= 240g * 1.0 cal/(g C) * 43 C = 10,320 calories
These are gram calories. In food Calorie (kg-calorie) units, it would be 10.432