(WEST LAFAYETTE, Ind.) -- Another diet myth bites the dust: products containing the calorie-less fake fat Olean, of fat-free potato chips fame, may make you gain weight, not lose it.
In a new study released Tuesday by Purdue University, researchers found that rats who were fed Olean-containing potato chips as part of a high-fat diet ate more overall and gained more weight than those who were fed a high-fat diet and regular, full-fat potato chips.
This counter-intuitive finding shakes the conventional wisdom that substituting lower calorie, lower fat foods for the full-fat versions will help reduce overall caloric intake and encourage weight loss.
"Fat substitutes can interfere with the body's ability to regulate what it eats, and that can result in overeating," said Susan Swithers, lead author and psychology professor at Purdue University.
But overeating may not be the only reason why fat substitutes make you pack on the pounds. Researchers suspect that fake fats actually tamper with our body's ability to digest and metabolize food, making us more likely to retain weight from what we eat.
"Our bodies make predictions on what to prepare to digest based on taste and how food feels in our mouth," Swithers said. When something tastes sweet or fatty, our body gears up to digest a high density of calories, stimulating the metabolism and triggering a chain of hormonal secretions to process the fat, calories, and nutrients."
"When we get cues that something is fatty, but no calories arrive -- like with fat substitutes -- our body gets confused," Swithers said. "This confusion can make the body stop preparing to digest fatty food when it does come."
Olean is the brand name for Olestra, a calorie-less, fat-free fat-substitute discovered accidentally by Procter & Gamble in 1968. Olestra was approved for use as a food additive in snack foods in 1996 and soon after became famous for its negative gastrointestinal side effects, including intense diarrhea and anal leakage.
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