ELi5: How do they measure calories etc for nutritional labels?

Question

I always wonder how “they” can know the exact amount of fiber, protein, carbs and sugars, etc when I’m reading ingredient labels.

PS: couldn’t decide between biology or chemistry flair since I guess my question relates to biochemistry! Haha

In: 527

Answer 1

Raw materials ie flour sugar butter etc already have approximately known macronutrient composition based on weight. For the meal plans I wrote for myself, I usually calculate everything based on this. Fats 9 cal per gram, protein and net carbohydrates, 4 cal per gram, etc.