Fat in the Stool of Persons Who Eat Olestra Potato Chips

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The summary below is from the full report titled "Positive Results on Tests for Steatorrhea in Persons Consuming Olestra Potato Chips." It is in the 15 February 2000 issue of Annals of Internal Medicine (volume 132, pages 279-282). The authors are R. Balasekaran, J.L. Porter, C.A. Santa Ana, and J.S. Fordtran.

What is the problem and what is known about it so far?

Olestra is a fat substitute that recently became available. It tastes like ordinary fats and is used to make some snack products, such as fat-free potato chips. The body does not absorb olestra and excretes it in stool. This means that people can eat food that contains this fat without absorbing any of the bad things (such as added calories and cholesterol) that come from eating food that contains fats that are absorbed. Abnormal amount of fat in the stool is known as steatorrhea. Steatorrhea occurs in diseases that cause problems with how a person absorbs nutrients from food. It is not known whether olestra excreted in stool interferes as fat to produce positive results on tests for steatorrhea.

Why did the researchers do this particular study?

The researchers wanted to find out how high the fat content was in the stool of people who eat olestra-containing foods.

Who was studied?

10 healthy volunteers.

How was the study done?

For 6 days in a row, study subjects ate 5 ounces of regular potato chips each day. For the next 6 days, they ate 5 ounces of chips made with olestra. The researchers measured the fat content of the stool of the study subjects by using several types of tests.

What did the researchers find?

When study subjects ate the olestra-containing chips, their stool contained amounts of fat that are commonly seen in people with diseases that cause them to be unable to absorb normal amounts of nutrients from food.

What were the limitations of the study?

This study included only 10 healthy volunteers under study conditions. The amount of fat in the stool may differ in people who are not healthy. In addition, the study subjects ate amounts of olestra larger than the amount most people would eat in real life.

What are the implications of the study?

People who eat olestra-containing food products can test positive for fat in their stool. Physicians should be aware of this so that they do not make incorrect diagnoses of malabsorption diseases in people who eat olestra. As an increasing number of olestra-containing foods become available, doctors must be sure to ask patients who present to them with complaints of malabsorption whether they eat any foods made with olestra.