Olestra is created by adding fatty acids to a sucrose molecule. The molecule is too large to be absorbed through the intestinal walls. It therefore, cannot be digested so does not add to the fat or caloric value of the food that contains it.
Proctor and Gamble currently holds the patent on Olestra. From 1971, when it was rejected by the FDA, they have been performing research and applying political pressure, and finally got the approval they desired in 1996. In 2000, the FDA mandated the following warning label on products containing Olestra:
WARNING: THIS PRODUCT CONTAINS OLESTRA. OLESTRA MAY CAUSE ABDOMINAL CRAMPING AND LOOSE STOOLS. OLESTRA INHIBITS THE ABSORPTION OF SOME VITAMINS AND NUTRIENTS. VITAMINS A, D, E, AND K HAVE BEEN ADDED.
The FDA removed the warning requirement in 2003, despite the fact that they had received over 20,000 complaints during that time, citing a study conducted by P&G on 3000 people who reported nothing more severe than increased bowel movements.
Health Canada has reviewed Olestra and has banned the product from food in Canada. Great Britain has also banned the product.
In the US, the CSPI (Center for Science in the Public Interest), a non-profit organization, paints a very different picture of the side effects than P&G. They noted side effects like:
explosive uncontrollable bowel movements
explosive sudden vomiting
The CSPI has been lobbying the FDA to ban Olestra, or at the very least, return the warning label to the front of products containing Olestra.
Fat free products are big business, and you can read a million studies on any product and pull information to support either side. The fact that several governments have looked at this and decided it was unsafe makes me lean strongly to the side of avoidance.
The foods that have Olestra added to them are not part of a healthy diet either before or after the chemistry project. However if I am going to eat chips, I am going to make a homemade olive oil version or I am going to just go for the gusto and grab the regular store bought kind. Either way, I know I won't be suffering some of those horrible sounding side effects like uncontrollable bowel movements. There is no chip in the world worth that!