Olestra

Olestra
Top: Generic 2D structure of olestra, where R = H or fatty acid group, C(O)CnHm
Bottom: Stereoscopic animation of a representative olestra molecule with 8 unsaturated fatty acid groups
Clinical data
Trade namesOlean
Legal status
Legal status
Identifiers
CAS Number
ChemSpider
  • none
UNII
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC
n+12
H
2n+22
O
13
(where fatty acids are saturated)
Molar massVariable
 NY (what is this?)

Olestra (also known by its brand name Olean) is a fat substitute food additive that adds no metabolizable calories to products. It has been used in the preparation of otherwise high-fat foods, thereby lowering or eliminating their fat content.

The Food and Drug Administration (FDA) approved olestra for use in the US as a replacement for fats and oils in prepackaged ready-to-eat snacks in 1996, concluding that such use "meets the safety standard for food additives, reasonable certainty of no harm".:46399 In the early 2000s, olestra lost popularity due to supposed side effects and is largely phased out, but products containing the ingredient are available in some countries. As of 2024, no products using olestra are sold in the United States.