Olestra is a synthetic fat that is essentially a combination of sugar and vegetable oil. The resulting molecule is unusually large, which makes it indigestible by the human body. As a result, it delivers zero calories, and functions as a fat substitute commonly used for frying. It is most popularly found in potato chips, where it decreases caloric value by 50 per cent.

The potato chip was first invented in 1853 by a Native American named George Crum, who was working as a chef in Saratoga Springs, New York. Reportedly, a customer found his French fries to be too thick, and rejected his meal. Crum retaliated by creating extremely thin and crispy French fries, which the guest actually liked. As a result, seven years later, he opened his own restaurant featuring a basket of potato chips on every table. By 1895, potato chips were being sold in grocery stores.

The earliest potato chips were most likely fried in cottonseed oil, which was the major vegetable oil in the United States at that time. This means that the chips would have contained 70 per cent unsaturated fat — the good kind of fat — and 26 per cent saturated fat — the bad kind.

Over the last century, the oil used for potato chips has changed considerably. Until 2003, Frito-Lay used partially hydrogenated oil, which contains the infamously unhealthy trans fats. Partially hydrogenated oil is also the absolute worst-choice oil, since it is noted for raising bad cholesterol and lowering good cholesterol. Since then, non-hydrogenated corn oil has been used, which is 85 per cent unsaturated and 15 per cent saturated.

Recently, Frito-Lay switched completely to NuSun — a healthier oil that is only 10 per cent saturated — which it has been experimenting with in its Canadian products for years. While the use of NuSun is a healthy improvement, Olestra has enabled the possibility of potato chips with no fat whatsoever.

While olestra seems like a magic ingredient that will allow us to consume limitless potato chips without increasing our risk for heart disease or making us overweight, it is not without its potential drawbacks. When olestra was first created, it was nearly used as cholesterol medication, because of its ability to bind cholesterol and prevent it from being absorbed. Unfortunately, in addition to cholesterol, it also binds vitamins and other fat-soluble nutrients to inhibit their absorption.

As a result, olestra is a controversial food ingredient, and joins the list of countless food additives that are legal in the U.S. and illegal in Canada or vice-versa — despite the fact, according to Stanford University fellow Henry Miller, that is the most tested food substance in history.

The potato chip has come a long way since it was first invented. While olestra as an ingredient might be too good to be true, NuSun illustrates how some advances in food science are making products like potato chips healthier.