About the calories when cooked

Hi
I have purchased a Tefal actifry and it has led me to ponder the question - If a potato is for example 100 calories raw uncooked, if it is cooked by boiling or baked or roasted without oil etc (basically cooked without any other calories added) Is it still 100 calories when its cooked or does different methods of cooking (again without adding ANYTHING) mean it comes to a different number of calories?

I hope this makes sense!

Jaycee x

Different methods of cooking give a different calorie content. Fo example 100g of baked potato has a higher calorie content than 100g of boiled potatos. This is because baking causes water to be lost whereas boiling causes water to be added.

The same is true for pasta. 100g of dry uncooked pasta has a MUCH higher calorie content than 100g cooked pasta. Most pasta has the same calorie content uncooked but different calories cooked given their different water absorbtion rates.

You are better off going by cooked weights if you can although sometimes that can be a real pain...

I am not sure I have found all of the discussions of this subject. Those I have read, like this thread, are concerned with gain or loss of weight of water, fat or alcohol, etc during cooking. As described by earlier posters, the weight and energy value of cooked-out and not eaten fat, for instance, can be subtracted from the uncooked food, . If energy values-calories per 100g were all on a cooked basis, as eaten, and we were weighing cooked foods then things would be straightforward. But I don't think we are. Nearly all data, particularly on supplier's nutrition labels, is uncooked and how many of us weigh or measure cooked food - it's usually hot! - and combined with other food components and how many of us collect and weigh cooked-out fat or boiled-off water. I always weigh or measure before cooking when it is easy. I am interested in whether the the energy changes in the chemical reactions in cooking eg changes in the proteins, etc, are significant, compared with the "quoted" energy values, endothermically adding to the value or exothermically reducing the value,and where such data can be referenced.

Thanks - David Webb