Calories. How do they work them out?

TRD66

How do the corporate eggheads work out how many calories are inf, for example, a chocolate bar? Is there are formula that's as complex as anything you've seen before, or is there a simple answer?

Similarly how do the good guys at MFP (or anywhere else for that matter) get their 'calories burned' for each exercise?

Snow3y

Calories:

1g carb = 4calories
1g protein = 4 calories
1g fat = 9 calories

I personally, along with many others, focus on macronutrient(protein, carb, fat) quantities rather than just calories.


Calories burnt can't really be accurately measured using MFP... But you could try a website 'fitocracy' which I find extremely accurate with regards to calories burnt performing an exercise...

athenasurrenders

http://www.slate.com/articles/news_and_politics/explainer/2004/04/how_do_they_measure_calories.html

You might enjoy reading this article. I remember doing the experiment in school where we set fire to shredded wheat and used it to heat water!

I wonder whether big companies send off samples to be tested to get their nutrition information, or if they work it out mathematically by adding up the quantities of ingredients which already have known values.

athenasurrenders

Oh sorry, I only answered half of your question. I know on an individual level you can have tests which identify the calories you are burning from your breath. I assume there are some studies out there that give average burns for people of various sizes doing various activities, but it's always going to be guess work on sites like this - even if it has your height, weight and gender it can't possibly account accurately for your fitness level or uneven terrain.