Hello and welcome to the Nutrition Diva podcast. I'm your host Monica Rinegall. If you're

a new listener, welcome. And if you're a long time listener, thank you for tuning in and

also for sharing the podcast with your friends and family.

Today's episode was suggested by listener James, who called into the Nutrition Diva listener

line with this question.

Hey Monica, this is James. I was wondering if you could devote an episode on calories and what

they are, how they're measured and how we process them even though they're just a measurement

of food and not actual food and what a bomb calorimeter is and all the problems with

counting calories. So that would be awesome. I love to hear that podcast. Thanks.

Thanks for this great topic James. So let's start with what a calorie is and how we know how many

calories a food contains. A calorie is a unit of measure, like an inch or a kilogram, only instead

of measuring length or weight, a calorie measures energy. Technically, a calorie is the amount of

energy it takes to raise one gram of water by one degree Celsius. Calories can be measured using

something called a bomb calorimeter. Isn't that a fun name? You might even have built a crude

version of a bomb calorimeter in sixth grade science class. In broad strokes, you submerge a chamber

in a bucket of water and you put a thermometer in the water and then inside that submerged chamber,

you set something on fire. The heat generated by the combustion raises the temperature of the water

in the bucket and you can measure that with the thermometer and then you can calculate the amount

of energy or calories or in the thing that you set on fire. So we used to use bomb calorimeters

to calculate how many calories a given food contains. These days, however, it's much more common

to estimate the number of calories based on how much protein, fat, and carbohydrate of food

contains and those amounts can be determined through chemical analysis. Now, when we're using the

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