Still, if you're trying to limit saturated fat in your diet by enjoying low- and fat-free foods, the trade-off may be worth it if you limit sodium in other areas.

CNN: How to be sodium savvy

You've been "conserving" calories for years -- with diet sodas, low-fat milk and lately with fat-free potato chips.

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Fat-free foods don't fit into a nutrient-dense diet unless they're naturally free of fats, like vegetables and fruit.

CNN: Get the biggest bang for your calorie with nutrient-dense food