Home Cooked - Will cooking INCREASE kcal?

amuseboucheUK

Hi all,

I do a LOT of home cooking for my family of 9 (2 adults & 7 kids) and the meals I produce are, on the whole, very healthy (it's just the quantity that I need to moderate!) ... so I'm cooking up my usual weekly "mis en-place" storm but have the old spread sheet open and the scales to hand as I add ingredients to my pans ... I will then weigh the finished products and should get a kcal / 100g out of it at the end (to allow for evaporation etc)

I also use a LOT of veg even in "meat dishes" - eg 500g of mince beef will do two meals for the 9 of us (a chillie and a bol) as I add lots of celery, carrot, onion, tomatoes and peppers etc to the mix to make 4kg of finished meals...

My query is if processing and cooking can increase the digestible calorie content of raw materials ... an example we are all familiar with, I'm sure, may be sweetcorn - the difference between eating the whole kernels or eating a whole corn "porridge" (sorry for the graphic nature if this illustration) ...

I'm wondering if there is a major difference or if it's not worth worrying about?

Right ... back to chilling Sunday's Stew!

Cheers, in anticipation,

Matt

Kymmu

I guess it's a question of the oils you cook in, the flours you thicken with and the sauces you add. These all have the ability to add calories, carbs and sugars respectively.
You would perhaps liquidise some of the fibre content the way a juicer does to an orange, depending on the dish and how it's cooked.

amuseboucheUK

Hi Kymmu ... I'm accounting for EVERYTHING that goes into the pan ... including Oils, Flours, Herbs, Spices, Sherry, vinegar etc... right down to the 1ml / 1g level ... nothing is left off the spreadsheet ...

I guess another example would be when one cooks onions or a steak ... the "brown" is burnt sugars that have been converted from starch / proties in the raw ingredient ... I think it was Valentine Warner (UK TV chef type person ) who described the frying pan (skillet) as man's external stomach ... LOL

Pebble321

As far as I'm aware, the cooking process itself doesn't add more calories.

I use the MFP recipe calculator and add all the raw ingredients then enter how many servings it makes, and it calculates cals/serving which works very well for me.
I think this is simpler than weighing the completed meal, and your spreadsheet would be able to do the same thing if you don't want to use the MFP tool.

amuseboucheUK

Thank you Ruby ... I was not aware of the tool ... that's fantastic! You are the precious stone your name implies! :-)

mfp_1

I read that it takes more energy to digest raw food than cooked food. So I think I know what you mean. But I haven't looked into it.

amuseboucheUK

It's a difficult one ... hmmm (Being a science student it also interests me...)

beckys19

Seems odd, but after looking up a few quick things it looks like it may, or may not... in 3 instances it gains slightly, (1.08 to 1.09 times the number of calories) in one it lost calories...... I am not sure just how big of a sample they use and if they test multiple samples of the same items both cooked and uncooked. If the number of samples per each item is small enough, individual variance between each item may show on these values. So, if they only tested 1 raw egg and 1 hard boiled egg, the results may not show a true average.

The old method of calculating calories consisted of burning the food and seeing how many degrees it heated some water. The new method involves calculating the calories from teh protein, carbs, fat and alcohol present in the items.
http://www.scientificamerican.com/article.cfm?id=how-do-food-manufacturers
Still, who knows if this is a 100% true representation of the calories in the item that was tested. Which *can* be different than the item you consume due to natural nutritional variance.

Personally, I just enter in all the raw values since that is easier to measure. It seems to work for me. :happy:


raw egg is 143 per 100g, hard boiled is 155 per 100g. Don't know how an egg can change weight by boiling....

http://nutritiondata.self.com/facts/dairy-and-egg-products/111/2
http://nutritiondata.self.com/facts/dairy-and-egg-products/117/2

chicken, half breast (boneless, skinless) 130 raw, 142 roasted (don't know if the sample they took was cooked skinless or if skin was removed after cooking on this though)

http://nutritiondata.self.com/facts/poultry-products/701/2
http://nutritiondata.self.com/facts/poultry-products/703/2

Asparagus 100g raw is 20 cal, boiled is 22.
http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2311/2
http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2312/2

Raw potato, large is 284, large baked is 278.
http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2546/2
http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2770/2


This is not an in-depth look by any means, but it is quite interisting.

amuseboucheUK

Wow ... great work there Becky ... thank you ...

It's quite confusing (for me) sometimes with what weights are being discussed ...

Some foods gain weight when being cooked (eg rice and pasta) for the water they take on to re-hydrate ... so no added kcals but the kcals / 100g (4oz) drops ... whereas others will gain calorific "mass" - eg tinned toms reduced down to make pizza topping by boiling off the water ... still the same kcals but weighs less...

I'm still not sure how the cooking process affects the available kcals ... :-(

Some research is required - I will search the Open Uni library sometime soon (off to see the Rugby - England V Ireland tomorrow so it will have to wait)

Cheers

Matt

MrsLong1980

Dear Lord man, I think I've just about burnt my yearly exercise calories reading and attempting to understand what this is all about! LOL Do you think maybe this could be over-analysing your calorie intake? The recipe calculator on MFP is a wonderful thing, does it all for you!

Kymmu

My head hurts.

amuseboucheUK

It's good to exercise the brain as well as the body ... and if I can occupy my time cogitating rather than snacking all the better!

Thanks for your help and support thou :-/

M@t

Kirsty_UK

As an ex-scientist I find the question interesting! From a pesonal food dairy perspective, I don't worry about it, I doubt it effects my intake as much as say, the inaccuracies on my weighing scales, the scrapings left in the bowl when I serve up, etc etc, but as a science question, hmmm.

No idea though sorry! I suspect it will effect what your body can absorb versus pass straight through you though.

helenium

I could see it working either way. Yes medium-cooked meat can have a higher calorie content that we can access than rare-cooked meat. But also burning food and oxidising it prevents us from doing so to produce energy...

kennie2

whenever i cook i just log the raw weight of the ingredient.
i think thats the most accurate

for example with pasta
it can be 75g raw
and then between 175-225 once cooked depending on how long you cook it for

so my suggestion is just log the raw food

tigersword

Cooking food does not change the calories of the food. HOWEVER, cooking food does change the weight of the food. Always measure food raw for calories, because raw weight will be consistent. Cooked weight can vary widely based on actual cooking method, cooking time, specific cooking temperature, final food temperature, carryover cooking, humidity, and other factors.

Example, if I start with 100 game of beef, and cook it 3 different ways, I can end up with 3 pieces of meat a the end that weight 95g, 85g, and 78g. They all have the same number of calories, as the weight difference is due to water weight changes.

beckys19

Cooking food does not change the calories of the food. HOWEVER, cooking food does change the weight of the food. Always measure food raw for calories, because raw weight will be consistent. Cooked weight can vary widely based on actual cooking method, cooking time, specific cooking temperature, final food temperature, carryover cooking, humidity, and other factors.

Example, if I start with 100 game of beef, and cook it 3 different ways, I can end up with 3 pieces of meat a the end that weight 95g, 85g, and 78g. They all have the same number of calories, as the weight difference is due to water weight changes.

Well, technically not so. Different methods of cooking may remove slightly more fat than others. I would think meat in a sausage caseing would retain a little more fat than the same meat removed from the link, then cooked (or if the link was just sliced and then cooked).

Yes, info like this is purely academic, since natural varience in calories, scale increments (and even individual scales might be a little bit off true), 'scraps' in the dish, and more will all play a part on the actual true caloric value of an item. That is why I am consistent with how I measure my food/ingredients (I weigh raw/uncooked), and when my results don't meet expectations, that is when I add more activity or reduce total calorie allowance.

That said, cooking is a chemical change in the food. It has been shown to reduce the amount of some vitamins in some foods, in others (such as asaragus) activates chemicals that make the food more appeasing (to most)... quoting Alton Brown, Age of Asparagus "Now what's really cool about asparagus is that it becomes two completely different vegetables, depending on whether the heat in question is wet or dry. Dry heat tends to emphasize amino acids, which create flavors that are almost meaty. Whereas moist cooking methods bring out the brighter, spring-like grassy flavors, which, I think, is a pretty good place to start.
"

If cooking can affect vitamins, it may have some impact, however slight, on how the body can break down and utilize the food, and the energy expended in that effort. While scientists probably have a pretty good idea how this all works and can get us very accurate results, there are just so many different mechanisims involved I don't know if we would ever get a 100% true result anytime soon.