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The skinny on fake fats

Love to snack on low-fat or fat-free potato chips, frozen desserts, cookies or other foods that, in their traditional forms, are dietary disasters? Thanks to fat substitutes such as polydextrose or olestra, people watching their fat intake can have the taste of the real thing with little guilt.

Studies show that people who choose lower-fat foods—including foods naturally low in fat—consume 400 to 500 fewer calories a day than do people who opt for higher-fat foods.

But consider these caveats:

  • Low fat doesn’t mean low calorie. Some low-fat or fat-free foods have more sugar—and, therefore, more calories—than the traditional version of the food has. Make sure the food you select is low in both fat and calories.
  • Portion size matters—a lot. Eating large quantities of anything is almost never good, and you could be taking on a boatload of extra calories.
  • Eating a lot of foods containing fat substitutes can have some undesirable effects. Eating excessive quantities of foods containing the ingredients polydextrose or olestra may have a laxative effect or result in loose or fatty stools. However, little evidence exists proving that eating these foods has long-term consequences.

On the positive side, some fat substitutes appear to go beyond reducing fat and calories in their benefits. Protein-based fat substitutes from milk powder, whey, soy or legumes may increase your diet’s protein quality and help give you a feeling of fullness.

Fat substitutes made with oat fiber or from fibers such as inulin, lupin fiber or Beta-glucan may improve dietary fiber consumption, regulate food intake and help manage weight.