Perhaps it could be better stated as: “cooked food provides more energy to the human body than does raw food”. The calorimeter bomb measures the total amount of energy in the food. Then a calorimeter bomb would measure the amount of energy in the waste. The total energy in the food minus what comes out as waste minus the energy required to digest the food is the energy available for the body to use.

strictly taking about energy: can the body use different types of food equally as efficiently: protein versus carbs (converted to sugars) versus fats. ditto different kinds of sugars.

And of course the body needs food for more than just energy (calories).

Another note, digestion starts in this order: in the hands, in the nose, in the mouth, and then from there. If we don’t touch, smell and chew our foods properly we are leaving out a huge part of how well we can absorb nutrients. Nutrition is important, even on a raw food diet. One can eat too many nuts and balloon to obese levels. Anyone on any diet can get fat if they’re eating too much or too much of something they don’t need.

Lastly, not all cooked food tastes better. I feel like crap after eating cooked food. I grew up sick, in pain, and skinny with a bloated belly. Eating high or 100% raw vegan is the only thing that has eliminated most of my health problems. Unfortunately, the issues return when I stray from that path. I keep my animal products and cooked food to a bare minimum. I am no longer sick, skinny, or in pain.

Different things work for different people. We all need to find what works for us individually.

The Wikipedia page on the Atwater convention gives some of the error bars on the component measurements.