Olestra is made from vegetable oil (a real fat), but it’s then processed to create a no-fat taste-alike. During the transformation, Olestra becomes a substance that can’t be broken down by the stomach’s digestive enzymes. That means that rather than being digested, the product—and all of its potential fat and calories—gets excreted. In other words, they leave the body before they’d have a chance to make you gain weight
Due to its indigestibility, Olestra consumption can lead to diarrhea, loose stool, and abdominal cramping, especially for daily consumption of 20 or more grams (which is about a two ounce bag of chips). Because of these possible side effects, the FDA has required that Olestra products have to carry the label: “Olestra may cause abnormal cramping and loose stool”
Other side effects that have been cited are “Oil Leaks” due to the viscosity of Olestra
Due to the lipophilic (hydrophobic) nature of Olestra, it can serve as a “sink” for other lipophilic nutrients such as the carotenoids and the fat soluble vitamins A, D, E, K. The significance of this is that as Olestra gets clumped into lipid droplets and excreted, it can take these vital nutrients along with it and reduce their absorption, depending on when the Olestra was consumed and how much was consumed
