[tryitnow]

How is that " the calories of a meal do not equal the sum of it's parts"?

That seems to violate the laws of thermodynamics.

[alphydan]

He may be talking about cooking. This could involve chemical reactions, or facilitate / slow the absorption of nutrients, therefore changing the effective caloric intake from various ingredients.

Thermodynamics should add up once you account for heating, cooling, evaporation, enzymes, waste, etc

[gohrt]

Cooking changes the caloric content of food. Not all of every ingredient gets all the way to the diner plate.

Biology is not thermodynamics. Humans are not perfect combustion engines.