Fake Fat Potato Chips May Make You Fat
August 2nd, 2011
By: Susan Lynn Peterson
Olestra, a synthetic fat substitute, may contribute to weight gain. In a study published in the June 20, 2011 edition of Behavioral Neuroscience researchers from Purdue University report that rats fed both low-calorie, olestra potato chips and high-calorie, high-fat (HF) regular chips gain more weight than rats fed just the HF chips.
In this study, rats were divided into two groups. The first group was offered high-fat potato chips and a rat chow that mimicked the high fat and high calories of the standard American diet. The second group was offered high-fat chips some days and low-fat olestra chips other days. The second group also got the standard rat chow. Rats that were offered the olestra chips ate more food, put on more weight, and ended up with more fat than the other rats. Once the chips were taken away from the rats, they did not lose the weight but stayed fat.
Researchers attribute the weight gain to interference in the body`s predictive mechanism. Normally, people and animals have the ability to judge the amount of energy in food and to compare it with the amount of energy that the body needs. If people or animals gain weight, it is because something has interfered with this natural homeostatic mechanism. The Purdue researchers believe that olestra confuses this mechanism. When rats taste fat but get no energy from it, they lose their ability to judge when they have eaten too much fatty food. They eat not just more chips, but more high-fat food in general. They get fat, and they stay fat.
Olestra, the fake fat used in the study, is a calorie-free fat substitute. Chemists create olestra by combining a vegetable oil molecule and a sucrose (sugar) molecule. The resulting molecule is one not found in nature. The human body cannot digest the molecule, making olestra calorie-free. In other words, olestra has the mouthfeel of fat but not the calories.
This recent study is only one in a series of studies that raise questions about olestra. Other studies have shown that it leaches both fat- and water-soluble vitamins from the body. Normal dietary fat carries fat-soluble vitamins into the body for use. Olestra, on the other hand, binds to these vitamins, but then because olestra can`t be digested, it carries the vitamins out of the body unused.
Chips, too, have raised a few eyebrows in recent studies. A study published June 23, 2011 in the New England Journal of Medicine pointed to potato chips as being one of the leading culprits in gradual weight gain. In a long-running medical study involving 120,877 people, researchers attribute 1.69 pounds of weight gain over four years to potato chips alone. This gain is the single greatest weight gain from any source.
The conclusion? Potato chips are, at most, an occasional treat, not a regular part of a healthy diet. And if you are going to eat potato chips, stay away from the olestra ones. They may cost you more than the few calories they save.