Does burned food have fewer calories?

Question

My kids asked me this and I didn't have an answer. I assume it does because the definition of a calorie is the amount of energy it takes to raise 1 gram of water 1 degree. So if you take away that energy, then you take away the calories.
+++ Please no hate-mail about dieting and kids, we're not on a diet, we eat very well and we're all a healthy weight. ;) We have no intentions of eating charcoal. +++

Answer 1

The answer is yes, but the difference is going to be small. Food is composed of proteins, fats and carbohydrates (I'm omitting all the other microelements for simplicity). All of them contain carbon, hydrogen and oxygen (and nitrogen in proteins). If you burn your food, you end up making complex polymers of these compounds and you also dehydrate (remove water) from them turning the food into undigestable products that are not taken up by the body.
An example: glucose upon heating turns into carbon, which cannot be digested and metabolized (C6H12O6 -> 6C + 6H2O). This is a simple case, oftentimes more complex molecules are formed, the idea is the same.
Still, a nutritional calorie and the physical definition of it are different things, although both are units of energy.

Answer 2

this is probably no longer enoough to make any distinction. And what you defined, BTW, is a calorie, in spite of the certainty that that may no longer the calorie that dieters use. The 'weight alleviation plan' style of calorie is one thousand of the 'actual' capability ? yet..... in case you burn something, it is going to type undesirable so consistent with danger a dieter ought to consume much less of it and drop extra pounds ? Doug

Answer 3

It's probably not enoough to make any difference. And what you described, BTW, is a calorie, but it's not the calorie that dieters use. The 'diet' kind of calorie is 1000 of the 'true' calories ☺
But..... If you burn something, it'll taste terrible so maybe a dieter would eat less of it and lose weight ☺

Doug