When Fat-Free Foods Make Less Sense

06/21/2010 08:05 am ET | Updated Nov 17, 2011

Raise your hand if you're a sour cream fan!

Whether dolloped with chives onto a baked potato, cooling a hot soup, or sweetened with freshly picked berries, there's nothing quite like it.

Traditional sour cream is a dairy product rich in fats (12-17 percent). It is made by fermenting cream with certain types of lactic acid bacteria. The fermentation process thickens the cream and sours it a bit, hence the name.

But alas, the fat content is high, and the calorie count too. And that's where the low fat and no-fat solutions come in. The question is, at what price?

What you need to know:

We took a look at three sour cream variations from Tillamook, considered one of the better-quality sour creams out there.

A serving size is two tablespoons, with 60 calories for the full fat product, 40 for the low-fat, and 20 for the non-fat version. As you would expect.

But then we inspected the ingredient lists:

Regular's Ingredients [3]:
Cultured pasteurized grade A cream and milk, enzymes.

Low-Fat's Ingredients [12]:
Cultured Milk, Cream, Nonfat Dry Milk, Whey, Modified Corn Starch, Sodium Phosphate, Guar Gum, Carrageenan, Calcium Sulfate, Locust Bean Gum, Gelatin, Vitamin A Palmitate.

Fat Free's Ingredients [12]:
Cultured Low-fat Milk, Modified Corn Starch,Whey Protein Concentrate, Propylene Glycol Monoester, Artificial Color, Gelatin, Sodium Phosphate, Agar Gum, Xanthan Gum, Sodium Citrate, Locust Bean Gum, Vitamin A Palmitate.

Basically the low and non-fat options had a big challenge once removing the fat: How to keep the "sour cream" product looking and tasting like a real sour cream? Food scientists started mixing various additives together until they reached the closest possible resemblance.

And what did they add? Propylene Glycol Monoester is an emulsifier that helps aerate creams (and dough for baking). Corn starch, Gelatin, Agar Gum, Locust Bean and Xantham Gum help with the viscosity of the product that is lost once the the fat gone.

While some people may revel in the 40 calories saved here, perhaps they should think about the bigger picture. With proper portion control and less junk food, the 40-calorie differential doesn't make sense. Especially since the synthesized alternatives don't taste as good as the original full fat sour cream.

Another issue to think about is the psychology of low-fat selections. I'm having a "good" non-fat product now, which means I have earned the right to eat something "bad" later. Or: I'll have the 16-oz steak with a baked potato and fat-free sour cream, instead of the 12-oz steak.

What to do at the supermarket:

When considering low-fat and non-fat options of your favorite foods, it makes sense to look at the calorie savings and weigh that against the changes in the product formulation. In some cases, it simply doesn't make sense.