Please show me the loss. Every time I try to find one I see that cooked meat is higher in vitamins and minerals than raw. I know that is partly due to water loss when it is cooked.
http://ndb.nal.usda.gov/
or
http://nutritiondata.self.com/
I had a nice reply written up but my computer decided to restart on me so you get the half-assed version.
Cooked pork shoulder.
Raw pork shoulder.
Here's the thing. There are gonna be "more" nutrients in 100 grams of cooked pork than in 100 grams of raw, which can be seen above. Why? Because cooked pork has less moisture in it than raw, so there's more matter per 100 grams of cooked than raw. However, you take away that difference, and there are less nutrients. Now this varies widely according to fat content, how it was cooked, in what, and for how long. Doesn't change the fact that there are less nutrients in cooked pork shoulder than raw.
Note the thiamin content. Even without the weight difference, there is much less in cooked than raw. Thiamin is one of the nutrients that is very easily damaged by heat. Ever wonder why thiamin is listed as an added ingredient on almost all processed foods? Because cooking and processing destroys a good chunk of it, and without adding more in, there wouldn't be enough of it in the food.
Also lower in cooked than raw: Niacin, B6, Pan acid, magnesium, and that's without taking into account the difference in cooked vs raw weight.
It's really not much of a significant difference, but that's not my point at all.
Effect of cooking on the thiamin content of foods
The effect of cooking on the digestibility of meat
The effect of heat upon the biological value of meat protein
A comparison of the nutritive values of raw, pasteurized and evaporated milks for the dog
Cooked meats and animal products (especially plant matter) are more readily digestible than raw. However, they not only lose some nutrients in the cooking process, but some are rendered inaccessible by the heat. Protein for example is damaged by heat so while there might be a lot of it in a chunk of cooked steak, it's not as easily accessed cooked than in it's raw form. Also, if the cooking is way overdone, the digestibility actually goes down as well as damages nutrients.
So while cooking may make that meat more easily digested, the nutrients are not as bioavailable as they are in raw meats. Which is what's important. If they are still there, but cannot be utilized as easily or at all in some circumstances, then I do not see why cooking is better than leaving it raw.
That is why I do not think cooking is better than raw. You can still see the nutrients, but they can't be used.
I will note this, though. Some nutrients in some foods are more accessible in cooked forms rather than raw. Vitamin A in carrots is many times more bioavailable when cooked than raw, so for some foods, cooking is better. However, that is often not the case with meat.
Another thing you will note in these studies is that cooking has an effect on the energy in the foods. It boosts it. They do not, however, state if the experimental animals gained muscle or fat.
My personal experience is in no way scientific or "credible" in any manner, but when Conker ate cooked foods for a short bit, he weighed more than when he ate raw. But most of that extra weight was fat, not muscle. Muscle does weigh more than fat, but when it's covered with fat, the dog is gonna weigh more anyways. So while on raw, though he weighs less than cooked, he was not fat, he was solid as a rock. After I took him off cooked foods he lost that extra fat. Several studies show that being lean is much better than carrying a bit of fat for the overall health and longevity of the animal.
I really like nutritiondata as a means to make up meals for my dog. However, there are many problems with it. It does not take into account where the foods were grown and in what season, what the cattle were fed, how old they are, and many other things pertaining to that field. Commercial foods have way less nutrients in them than sustainably grown (organic, but I don't mean commercial organic) and nutitiondata does not have much info on those.
It's a general guideline, not law, as to what nutrients are in the food. Just like the feeding instructions on a bag of kibble.