Calories

[Caran]

Having just watched Secret Eaters it got me thinking, how do they work out how many calories are in foods? Anyone got any ideas?

[LazyGun]

well the old fashioned way was,essentially, to burn it in something called a bomb calorimeter.

Nowadays its a bit more refined - identifying the constituents, breaking them down into their food groups, things like Kjeldahl analysis to directly measure the nitrogen in food and indirectly the amount of protein.

[Caran]

Thanks LazyGun, I didn't understand any of that, science is not my strong point.
How can burning something tell the amount of calories?

[Iluvspikey]

A calorie is a unit of heat

[tiggerblue10]

Video here:

http://blogs.howstuffworks.com/2010/05/27/how-is-the-amount-of-calories-in-food-determined/

[society]

They measure the amount of energy that's derived from the food, convert and calculate.

[Old_Geezer]

Calories is energy. By burning something it releases that energy. So you can measure what energy came from the quantity of stuff you burnt.

[237SJ]

It`s the amound of energy it takes to heat one molecule of water by one degree C (I think)

[Caran]

That's all scary, I wish I hadn't asked now, I think I will never eat again!

[Caran]

Thanks Headwreck, you have all been very helpful.

[Slooow_Jo]

all the science stuff you've just been told, using that they figure out calories in other stuff too, & I THINK they then decide what can see what off!! what burns what, i.e eating celery gives more energy burn so won't have a calorie value???
I could be wrong ;)