Fat Content of Human Food

Let’s talk about labeling for human foods, so we can better understand how much fat is in them. The first thing you should know is that this is always going to be guesswork on our part because nutrition labels for human food do not list the moisture content. What we need to do here is combine data with common sense in order to come up with a best guess about whether we can try a food.

This question often comes up in the context of treats, and my usual response is not to chance it, period. But sometimes we have other reasons for needing to give human foods. On our Facebook group there was a recent discussion about how to entice a dog to take a pill that can’t be cut or crushed. Most of us will want to hide that pill in something the dog will eat, but what? Let’s look at some labels and see if we can figure this out.

The example label I’ve posted here (you can click on it for a larger version) shows a lot of information, but it’s tricky to interpret. Most of us would want to look at that label and say this food is 10% fat, because that’s what the label says, right? Well, no. What that number to the right actually means is that one serving of this food will provide you with 10% of the total fat recommended for the average person to consume in a day.

A better way to approximate fat content is to look at the serving size and the number of grams of fat the food contains. The serving size for this food (top right) is listed as 55g, or 55 grams. The amount of fat in a serving is listed as 8 grams. Then we do a little math: grams of fat per serving divided by the total number of grams in a serving, in this case it’s 8/55. You can then multiply this result by 100 to get the percent of fat per serving, which is what we really need. Here’s how this example works out:

    (8/55)*100 = 14.5

    The percent of fat per serving is 14.5%.

But now we need to talk about dry matter percents, which is what really counts. The true percentage of fat in any food can only be correctly described when we adjust for the moisture content of that food. This label doesn’t tell us how much water is in the food, so we can’t do a calculation to determine this. All we can do is look at the food and make a decent guess. If the food is moist or wet, we can assume that the actual fat content of digestible matter will be significantly higher than what we’ve just calculated. If the food is dry, like a cracker, we can assume that the number we’ve calculated is close to correct.

In this case, that’s a significant amount of fat, even for a dry food. I like to see numbers closer to 4% and below. That’s based on the dry matter content of the canned prescription diet that’s most often fed to our dogs, which is 4.1% fat, as calculated here: http://fnae.org/dmb.html

I hope this is helpful!

Louie’s mom is now retired from her previous work at the University of California, Davis.  She works part-time as a pet sitter, caring for others’ pets in their absence, and functions as the admin of the Canine Lymphangiectasia Educational Support Group on Facebook.  Donations through PayPal help her find the time to continue to provide information and research to others struggling with CIL.  If you find this information helpful, please consider a small donation.  Thank you.

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