Are calories extracted in the same way from different foods?

Are calories extracted in the same way from different foods?

The body can only fully extract calories from a solution of sugar or glucose. The degree of assimilation depends on the composition of the food and on the eaters themselves. Fiber is completely indigestible. Poorly digested proteins and polysaccharides of fungi, some algae.

Most Asian adults are unable to extract calories from milk sugar because lactase is not synthesized in their bodies. Chopped foods, boiled or stewed are digested better. Finally, digestion itself requires energy.

So the number of calories actually consumed is always less than the energy value of the product indicated on the package.