Does cooking alter the calorie content of food?

I am not a nutrition expert, but I don't believe cooking any food changes it's caloric value. Cooking (the kind of cooking actually = frying vs steaming, etc.) can change the nutritional values, though. Also, anything you add to the food while cooking it, salt, other seasonings, etc. can impact the caloric intake - oil in the pan before you put the chicken in, etc. These are often hidden or forgotten calories that frequently don't get counted. But 4 ounces of chicken breast raw or cooked contain the same calories unless something else is added.

Cooking just about anything will take some of the moisture out and lower the weight of the thing. Also, what you cook it with/in may alter it's value. In most case though it's nominal.

See now thats a very good question. I know meat changes ounces when its cooked, usually drops an oz. Hopefully, someone has the answer. I usually go with after cooked amounts.

I think it is actually water content that cooks out of the food when it is cooked rather than the meet actually changing in weight. I think that when the package indicates a calorie content - they are identifying the content of the raw meat - cooking doesn't actually change that, it may, however reduce the amount of water, thereby reducing the "actual weight of the food item." So, when you are preparing a meal, you weigh the meat i.e. chicken breast before you cook it - that is the amount of calories you would note as being consumed based on the packaged information provided for that particular weight of meat. i.e. the package states 1 serving is 3 ounces of chicken breast - with specific calories; you weigh out 3 ounces of chicken breast and cook it and the calories are still the same as they were before you cooked it unless you add oil, seasonings, etc.

But if you cook ground beef for example you are actually cooking fat out of the dish too which technically does change the content, but it wouldnt be measureable.
Chicken and pork etc are lean, you are right you are losing water

Great question! I have wondered the same thing.
Go by the weight for meats, chicken, etc. before cooking or after for calorie count?
I usually go by the calorie count recorded in the database for how the item is cooked. Say broiled vs fried.

Yeah, meat's a whole different thing. If you broil a steak, fat drips off as well as moisture (ever look at the drip pan on that George Foreman grill?), but a potato or any other vegetable just loses water, if anything. Pasta and rice gain water. In a strictly scientific manner, it might be true that food loses a couple of calories in the cooking (since a calorie is actually a measurement of energy/heat), but since we are not completely destroying the food and burning it to cinders, it doesn't change enough to make a difference to us.

So, except for meat (which can drip off fat, which is full of calories), you can add up the calories of all the raw ingredients and get the number of calories you are consuming. For meat, check the cooking methods to determine which choice to use. And for God's sake don't FRY anything!

I always use the raw, pre-cooked weights. Be aware - this is still vastly different than the frozen. Example, tonight I am making chicken. The recipe calls for 1/2 - 3/4 lb of chicken. So I measure out FROZEN 10 oz. Once it was thawed and I'd poured off all the frozen water/juice - 8.5 oz. (was checking to make sure it wasn't not enough chicken now, lol). While draining off meat fat while cooking can save you some fat, since it is immeasurable and varied based on the cut of meat and how much fat was on it before, I always just figure if I saved myself some fat - BONUS.

There's really no way to figure it out yourself and I don't trust user entries like "chicken, grilled" with the quantity of "1 piece." Mainly this is just me being persnickety and keeping in mind that I've encountered multiple entries for packaged food on the database the user felt the need to specify was "correct" in the title and then left off nutritional values like sodium - I guess cuz they weren't tracking them.

I'd rather not account for the dripped fat and overestimate my calories than underestimate and eat too much without knowing it.

That's a good question and I think you should, but how much I don't know..
For example if you have a frozen raw patty of sausage and cook it.. it renders a lot of fat out of it. And unless you drink it or add that rendered fat back into the meat.. it should drop the caloric count, right?
It'd be impossible to count accurately because people prepare their foods differently. My wife and I like sausage and bacon crisp, so we render it a little longer. I suppose I could pour that fat into a container and weight it and count 9 calories per gram (IIRC that's the caloric intake of fat)

http://www.livestrong.com/article/336835-why-do-caloric-counts-change-when-cooked/

Copy & paste the link into your web browser to read the article.

The components of food that contribute to the calorie count are protein, carbs, and fat. As others have mentioned, it is common to lose fat as a result of cooking because it liquifies. But, as far as protein and carbs, you aren't going to heat your food enough to break down the protein and carbs enough to lower the energy content. If anything, you will do the opposite by making the food easier to digest and therefore absorb.

Ooh very glad others feel the same way and it's not such a daft question after all :laugh:

I find it easiest to weigh the raw ingredients and track those. so for example tonight I cooked some homemade potato wedges - I cut some raw spuds into wedge shapes and weighed them out (200g), parboiled, then put in a roasting tin and tossed with a tsp of olive oil, some salt & pepper and a few chilli flakes and put in the oven until they were lovely and golden and crispy.

So for this I added 200g raw potatoes and 1tsp olive oil to my diary.

I had a little go on the 'My Recipes' bit of the website earlier and it looks like that works by just totalling up the nutritional info from the ingredients, so I guess I'm doing things the right way....

So to take this a little further, if I were to bake a cake, would I just total up the nutritional info of the ingredients eg 200g flour, 200g sugar, 4 eggs etc? Or does the 'chemistry' of the baking process alter the nutritional info? Is the end product simply a sum of it's parts, in nutritional terms?

Glad I've sparked off an interesting discussion! :blushing:

Claire

Regarding the cake:

Measure before or after baking. It is the same either way.

http://www.newton.dep.anl.gov/askasci/chem03/chem03809.htm

I have been wondering the same thing for a while.
I was able to find this article on the subject that is based on scientific research.

http://blogs.discovermagazine.com/crux/2011/12/08/why-calorie-counts-are-wrong-cooked-food-provides-a-lot-more-energy/#.VD2YJbB4qIR

The basic idea within it is that when food is cooked, it becomes more easily digested by your body. So if you eat a piece of raw meat, it will take your body a lot of energy to break it down and get the calories out than if you cooked that same piece of meat. Cooked meat and vegetables have already been broken down by heat so your digestive system can get more calories out of the food and digest it more efficiently.

Also, many vitamins cannot survive exposure to high heat over prolonged periods of time, so you should consider that for your micronutrient make-up.

However, I haven't been able to find a way of tracking how many real calories or vitamins you would be getting from food that is cooked v raw.

I thought of another example where cooking would reduce calories. Heating up sugar to the point that it caramelizes also alters the chemical structure.