Fat Substitute May Increase Weight Gain

WASHINGTONThe synthetic fat substitute olestra that is commonly used in snack foods may interfere with the bodys ability to regulate food intake and lead to inefficient use of calories and weight gain, according to a new study published in the journal Behavioral Neuroscience.

Researchers at Purdue University studied laboratory rats that were fed either a high-fat or low-fat diet. Half of the rats in each group also were fed Pringles potato chips that are high in fat and calories. The remaining rats in each group were fed high-calorie Pringles chips on some days and low-calorie Pringles Light chips on other days. The Pringles Light chips are made with olestra, a synthetic fat substitute that has zero calories and passes through the body undigested.

For rats on the high-fat diet, the group that ate both types of potato chips consumed more food, gained more weight and developed more fatty tissue than the rats that ate only the high-calorie chips. The fat rats didnt lose the extra weight even after the potato chips were removed from their diet.

The findings suggest a low-fat, low-calories diet might be a better strategy for weight loss than using fat substitutes.

Food with a sweet or fatty taste triggers various responses by the body, including salivation, hormonal secretions and metabolic reactions. The researchers theorized fat substitutes can interfere with that relationship when the body expects to receive a large burst of calories but is fooled by a fat substitute.

The rats fed a low-fat diet didnt experience significant weight gain from either type of potato chips. However, when those same rats were switched to a high-fat diet, the rats that had eaten both types of potato chips ate more food and gained more weight and body fat than the rats that had eaten only the high-calorie chips.