In 1880s, Wilbur Atwater conducted experiments burning food items. A highly simplistic outcome of this experiments was the following equation:
X = 4*Carbohydrates + 9*Fat + 4*Protein
This output is followed the food industry till date.
What is this equation supposed to measure?
Show Answer
Calories in the food (including the number found on the label)
The experiment burned different food stuffs (while subtracting some fudge factors) to calculate the calories in our food. For every gram of Carbohydrates & Protein, 4kcal is released & for every gram of Fat, 9kcal is released. While not being super accurate, these results give a good indication of calories in food.
Watch this great video by Howtown on the subject.