Calculating the calorie count of your food is easier than you imagine. You can make a calorimeter at home, and measure calories with just a couple of stands, a graduated cylinder, a good thermometer, and a good scale. (And by disabling the fire alarms in your building.)
To get a really accurate calorie count, you’d need some high-tech equipment, but if you want to double-check that your hunk of fake butter really is “lite,” this set-up should do it. Most importantly, you need a few good measuring apparatuses. Get a good thermometer, a good graduated cylinder, and a good scale.
Slightly less important is the set-up that you will use to burn the food. For that, you can get something as simple as a camp stove set, or even a bit of cork with a bent paperclip stuck to it (to hold the food), an inverted tin can with holes cut in it (to hold a flask of water the way a burner on a stove holds a pot), and the flask itself.
First, use the graduated cylinder to carefully measure the amount of water you’ll use before pouring it into the flask. Second, measure the weight of the food you intend to skewer with the paper clip. (Keep the amount of food small. If you boil the water, you’ll ruin the experiment by reducing the total amount of water in the flask, and making the water hit a temperature ceiling.) Finally, measure the starting temperature of the water.
You’re ready! Set the food alight. Measure the temperature of the water before and after the the food has burned to a crisp.
To figure out the amount of calories in the food you just burned, multiply the temperature change, in Celsius, by the number of grams of water being heated. (You would also multiply this by a conversion factor, but that happens to be 1 calorie per one degree change in each gram of water, so you just need to multiply by one.)
If you’re an American, the number you get will seem high. That’s because we measure our food in kilocalories, without explicitly calling them kilocalories. (This causes sticker-shock in Americans who go abroad and find out a can of Coke has 140 kilocalories.) Divide your total calories by one thousand to get a more familiar calorie count. Then enjoy whatever portion of your food you didn’t just burn, secure in your knowledge of its nutritional value.