Total fat in foods? Huh?

Most health gurus suggest no more than 30% of calories be from fat. Monosaturated and polyunsaturated fats should make up the majority, with less saturated fat, cholesterol and trans fatty acid structures (where trans refers to the position of the largest groups around a double bond in an unsaturated fat).

Lots of times (and by no means always) when I see the calorie content on a popcorn package or box of crackers, the amount listed under total fat per serving is not equal to the sum of the totals for monounsaturated, polyunsaturated and saturated fats. The amount for cholesterol is usually listed separately and is much smaller than the other fats for most foods.

So what type of fat is the missing fat? Is this only done for products that use various sources of fat of various saturation? Is it a mistake? I understand it would be prudent to ASSUME all the missing fat is saturated, but what am I missing here?

I’m going to guess and say it’s because the labels are approximate readings.

Example: (and I had to look at everything in my entire kitchen to find something that showed the fats broken down into more than “Total” and “Saturated!”)

Total Fat - 2g
Saturated fat - 0g
Polyunsaturated Fat - 0.5g
Monounsaturated Fat - 0.5g

I would assume that the Poly and Mono numbers were more like .63489203 grams of fat, which they rounded down to .5 for simplicity. The Saturated fat is probably a small enough amount to be considered 0, but is not actually zero. In other words, the Poly and Mono fats are slightly more than the .5g, and the Total fats are slightly less than 2g.

BTW, in order to determine the fat percentage of a food you take the total fat grams and multiply by 9, which is how many calories a fat gram has. You then divide that number by the total calories and that gives you a percentage of how much of the calories come from fat. In other words: Cheerios have 2g of fat per serving and 110 calories. 2 x 9 = 18 / 110 = .1636. So 16% of the calories come from fat. Sneaky, eh? There is a number next to the Total Fat column that says 3%. That’s the estimate of how much fat this would be in a diet based on a daily intake of 65-80 grams of fat (according to the tiny print at the bottom of the chart.) It has nothing to do with the percentage of calories from fat. Likewise, when something says “95% fat free” that doesn’t mean that only 5% of its calories come from fat, it means 5% of it IS fat!

I understand all that and thank you for your reply. But rounding doesn’t really explain the example you describe to my satisfaction. If all these numbers are significant to one decimal place, even if they aren’t exact the total fat should not be more than 1.3 grams – and it is. What’s the remaining stuff?

I should note the examples I have seen would list the total fat as 2.0 grams rather than 2g (as you did). There are also several times when the discrepancy has been more than 2 grams. Rounding is not a possible expalnation in many of the examples that I have seen. It might be for your example.

The missing fat composed of trans fatty acids. As you mentioned, trans fat isn’t saturated, but for some reason the FDA doesn’t allow labeling it as monounsaturated or polyunsaturated, thus it doesn’t get labeled at all.

There’s some more info here, about half way down the page:
Saturated vs Unsaturated Fats vs Trans-Fat


Thanks. While I considered this possibility, I actually thought it more likely they were lumped in with the unsaturated fats. Guess the same laws apply here in Canada too.

Arjuna34 beat me to it. But here’s a pretty good article on trans fats from the Center for Science in the Public Interest.

That’s because cholesterol isn’t a fat. It’s often found in fatty foods, and certain fats can cause your body to produce it, but chemically, it’s much more closely related to certain hormones.