Here are some interesting points from a Discovery article by Richard Wrangham
http://blogs.discovermagazine.com/crux/2011/12/08/why-calorie-counts-are-wrong-cooked-food-provides-a-lot-more-energy/His claims:
-
no experiments had been published directly testing the effects of cooking foods on net energy gained or lost through processing.
- some peer commentaries were dismissive of the idea that cooked food provides more energy than raw
- (after experimentation on both plants and meat)
cooked food provides more calories than eating the same foods raw
- (therefore) the (usual) calorie counts are routinely wrong
-
raw-foodists are thin compared to those who eat cooked diets
- the average woman on a 100% raw diet did not have a functioning menstrual cycle-?
-
about 50% of raw-foodist women entirely stopped menstruating-?- direct quote (When a raw-foodist’s reproductive system does not allow her to have a baby even when her diet is composed of processed, high-quality, agricultural foods, the obvious explanation is that she is not getting enough calories.)
- (in a lab setting testing mice) -
mice gained more weight (or lost less weight) on (the same) cooked food than on raw food (pounding food had very little effect)*
- (two major reasons why cooked foods provides more calories than raw foods) 1. muscle proteins, like the sugars in cooked starch, open up and allow digestive enzymes to attack their amino acid chains; 2. cooking does the same to collagen
- the mechanism for 1 & 2 is not understood
- however,
mice had a spontaneous preference for eating cooked meat over raw- The more highly processed (cooked and fine ground*, the more calories the body can extract from them
- Author is confident the increase in
calories of cooked foods will be much higher than 10% (25-50%)
* conflicting point on pounding/fine ground foods---
I have read (so have always understood that) cooking opens up more calories for assimilaltion. RW indicates the general assumption by biologists and the general population is that the calories are the same.
On the other hand, it seems intuitive that cooked foods would be harder to digest and therefore would take more calories to digest which is what this thread seems to suggest.
The idea of length of time on raw foods may come into play is interesting. Does the body adapt, how and what are the end results?
How important was the discovery of fire and cooking of meats to caloric improvement and was there some important indications to brain size and cognitive skills?
(Does this mean sugars in raw fruit are less fattening? I suspect a sugar - sucrose/fructose variety - is a sugar regardless its renderings)
---
I am going to keep better records regarding preparation and processing (cutting and cooking) of my food.