How to calculate caloric intake of nutrients

A paper I saw (I think someone in this group cited it) suggests that the
caloric intake target of cats yields "a macronutrient energy composition of
52% protein, 36% fat and 12% carbohydrate."

My question: How do I calculate caloric intake of macronutrients? Is that
pretty much the same thing as the nutrient composition? In other words, if
a food is 50% protein on a dry matter basis is that the same thing as
saying 50% of the calories come from protein?

By the way, here is a summary of the paper:
http://www.eurekalert.org/pub_releas...-wcf022411.php

Thanks.

JEP

"JEP" wrote in message
.130...
A paper I saw (I think someone in this group cited it) suggests that the
caloric intake target of cats yields "a macronutrient energy composition
of
52% protein, 36% fat and 12% carbohydrate."


My question: How do I calculate caloric intake of macronutrients? Is that
pretty much the same thing as the nutrient composition? In other words, if
a food is 50% protein on a dry matter basis is that the same thing as
saying 50% of the calories come from protein?

No. Protein and carbohydrate contain 3.5 kcal/gram and fat contains 8.5
kcal/gram. Thus 36% fat contributes more calories than 52% protein.


DMB doesn't tell you the amount of the nutrients your cat is actually
consuming or how much food to feed to meet the cat's target energy and
nutrient requirements. DMB is only good for comparing foods with different
moisture contents. The most accurate method for determining the caloric
density and nutrient content of pet food, how much of a nutrient your cat is
actually consuming, and how much to feed in grams or ounces is on a caloric
basis - IOW, #grams/100 kcal. You must use the "as fed" analysis for
caloric density and feeding calculations.




By the way, here is a summary of the paper:
http://www.eurekalert.org/pub_releas...-wcf022411.php

Thanks.

JEP