RunnerKim
04-03-2001, 10:57 AM
I'm hoping someone can explain this to me...
It's my understanding that the calories of a food are comprised of carbohydrates, protein and fat. Given that carbs and protein have 4 calories per gram and fat has 9 calories per gram, shouldn't the totals add up to the calories?
For example: The nutritional information for the Zucchini Parmesan (found in the on-line recipe search) is:
Calories 135; Carbs 15.4g; Fat 4.6g; Protein 9.8g
So theoretically 135 = (15.4 x 4) + (4.6 x 9) + (9.8 x 4)
But it doesn't 135 = 142.2
I've noticed the older CL recipes don't always work out but that ones from the past year at least all seem to work out exactly. However, most product labels and some of the foods from the USDA on-line database can be way off - over 30 calories difference for a single serving. I understand some could be due to rounding as calories always seem to be listed in increments of 5 - but that doesn't account the large discrepencies or the ones from the USDA database (http://www.nal.usda.gov/fnic/cgi-bin/nut_search.pl) which are carried out to 3 decimal points.
Kim
It's my understanding that the calories of a food are comprised of carbohydrates, protein and fat. Given that carbs and protein have 4 calories per gram and fat has 9 calories per gram, shouldn't the totals add up to the calories?
For example: The nutritional information for the Zucchini Parmesan (found in the on-line recipe search) is:
Calories 135; Carbs 15.4g; Fat 4.6g; Protein 9.8g
So theoretically 135 = (15.4 x 4) + (4.6 x 9) + (9.8 x 4)
But it doesn't 135 = 142.2
I've noticed the older CL recipes don't always work out but that ones from the past year at least all seem to work out exactly. However, most product labels and some of the foods from the USDA on-line database can be way off - over 30 calories difference for a single serving. I understand some could be due to rounding as calories always seem to be listed in increments of 5 - but that doesn't account the large discrepencies or the ones from the USDA database (http://www.nal.usda.gov/fnic/cgi-bin/nut_search.pl) which are carried out to 3 decimal points.
Kim