That's the startling result of a Purdue study on rats, using P&G Pringle's chips.
The P&G brand name for the fat is Olean, and the compound's patent protection ran out in the 1990s.
In the study, conducted by the school's psychology department, some rats were given just high-fat Pringle's, others a mix of chips, including some with Olestra. Those that had the Olestra chips consumed more food and got fat. Worse, they kept consuming more food even after being taken off the Olestra chips, and stayed fat.
Olestra is no longer a material business to P&G, which had revenues of over $78 billion last year. Sales peaked at about $400 million in the late 1990s, and were then cut in half following the imposition of an FDA warning label on side-effects.
But P&G's Light Lays and Pringles Light chips still contain the compound. The company also sells a fat called BakeLean with it. And the company's PGFoodingredients Web site indicates over 6.6 billion servings of Olean have been consumed.
All of which may mean a string of expensive lawsuits from fat people who bought Olean's “zero fat, zero cholesterol, zero calories, great taste” tag line.
This study follows a 2008 piece by the same Purdue research team which found that artificial sweeteners can be linked to weight gain, because they too cause people to consume more food.
P&G discovered the compound in 1968 and first approached the FDA about it in 1971, ignoring agency concerns that it might lead to more consumption of food.
In the end the FDA was proven right by the science. It's the plaintiff's bar that will be salivating now.
Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours. I launched ZDNet's SmartPlanet Health site in 2009, and this is the kind of story I did there.