If you think buying food that's labeled "low fat" or "low sodium" is more nutritious or healthier for you — you might be right and you also might be mistaken.
Confused? A new study by Duke University researchers took a look at the nutrient claims of more than 80 million foods, and examined how closely the claim of "low" calories, sugar, fat, or salt was associated with true nutrient density. Nearly 15 percent of foods and 35 percent of beverages studied carried one of these "low-content" claims.
The study, published Wednesday in the Journal of the Academy of Nutrition and Dietetics, found foods with a low-content nutrient claim truly did contain a lower amount of the nutrient described — whether calories, fat, salt, or sugar.
But at the same time, this description could confuse consumers. Here's how: regulations for a "low" or "reduced" nutrient on a label only refer to changes from the original food, not for a whole food category. While the particular single nutrient might be reduced, other nutrients are not.
So you're not guaranteed a smarter choice if you only look at one particular nutrient.
The most important finding of the study is that the low-content claim was not necessarily associated with a more nutrition-rich product. There was a wide variability between the claims made and the nutritional density of the food.
Read the back label
Consumers need to read the whole nutrition label carefully to know if they're selecting the most nutritious foods. Read the specific nutrient content per serving on the back of the package label and not only the general "lower in" guide on the front.
The guidelines for "lower", "reduced", and "free" terms on a package are tightly regulated by the government and are well defined. Here are some of the most popular labels and what they mean:
- Low calorie — 40 calories or less per standard serving.
- Reduced/less calorie — at least 25 percent fewer calories per serving compared to the standard food.
- Low fat — 3 grams or less per standard serving.
- Reduced/less fat — at least 25 percent less fat per serving compared to the standard food.
- Low sodium — 140 mg or less per serving.
- Reduced/less sodium — at least 25 percent less sodium per serving compared to the standard food
- Reduced/Less sugar — at least 25 percent lower in added sugars compared with the standard serving of the original food.
- Sugar-free — less than 0.5 grams of any form of sugar per serving; does not mean calorie free.
- No added sugar — a product can still contain natural sugars, like 100 percent fruit juice/fruit sauces or milk, but no additional sugars of any kind.
Studies like this continue to point out the importance of being an informed consumer. When it comes to label reading, and when you see a term like reduced, free, or low, your next question should always be "compared to what"?
Madelyn Fernstrom, Ph.D, is NBC News Health and Nutrition Editor.