Your doctor has suggested you have a 72 hour fecal (stool) fat test as part of the evaluation at National Jewish Health. A 72 hour stool fat test is a diagnostic test that will allow your doctor to evaluate the amount of fat you digest and absorb. This test can help your doctor determine a diagnosis and the best treatment for you.


Preparing for the Test

You will need to eat 100 grams of fat each day for 5 days. This may be more fat than you normally eat on a daily basis.

You will need supplies for the stool collection (white collection hat for the toilet and a large plastic stool container). You can get these two items in the Adult Clinic Phlebotomy area.

Avoid taking medication that prevents fat absorption during the 5 days of the test. Examples include: orlistat (Xenical® and Alli®).


During the Test

Days 1 thru 5:
  • You will eat 100 grams of fat each day.
  • You will record the amount of fat you eat each day. See the attached sample record for your use.
Days 3 thru 5:
  • You will collect all the stool you produce each day. Place the white collection hat in the toilet to collect the stool. After you collect the stool in the hat, transfer the stool to the stool container. Keep the stool container in the refrigerator until the end of the test period.
  • Once the test is complete after day 5, bring the stool in the stool container to the lab within 24 hours.


Length of the Test

The entire fat test takes 5 days once you begin the 100 gram fat diet. The doctor will review the test results and discuss them with you at a later date.


Day of the Test

On the day of your scheduled test, check in at the Front Desk. If you have questions please call 303.398.1355.


How to Read Food Labels to Determine Fat Content

Nutrition Facts

Serving Size 1 slice
Servings per container 6

Amount per Serving
Calories 160

Total Fat 10 grams, 15%
Saturated Fat 2.5 grams, 11%

There is a nutrition label on prepared foods that says Nutrition Facts. Look at this sample nutrition label. Determine the grams of fat in a prepared food you eat by following these steps:

  • First, check the serving size.
  • Second, check the total fat in grams. This shows the amount of fat in one serving.
  • Third, multiply the number of servings you ate by the totals grams of fat in one serving. This results in the total fat grams you ate.
  • If you ate 2 servings and the total fat per serving is 10 grams, you ate a total of 20 grams of fat.


Foods Higher in Fat

This table contains common foods you may eat and the estimated amount of fat per serving, listed as over 15, 15, 10 and 5 five grams of fat per serving. If there is a nutrition label on the food, check the label for total fat.

Foods Containing Over 15 Grams of Fat Per Serving
Sausage (3 ounces) 25 grams of fat
Fried chicken breast with skin 25 grams of fat

Foods Containing 15 Grams of Fat Per Serving
Avocado (½ medium size)
Burrito with beef, beans and cheese
Cheesecake (3 ounces)
Hamburger patty
Steak (9 ounces)
Pork chop

Foods Containing 10 Grams of Fat Per Serving
Bacon (2 slices)
Cheese, cheddar (1 slice)
Cottage cheese (1 cup)
Egg (2)
Ice cream (3/4 cup)
French fries (small size)
Mashed potatoes (1 cup)
Milk, whole (1 cup)
Pizza, cheese (1 slice)
Potato chips (1 ounce)

Foods Containing 5 Grams of Fat Per Serving
Almond butter (2 teaspoons)
Butter (1 teaspoon)
Cream cheese (1 tablespoon)
Cream (1 tablespoon)
Ham, deli, 2 slices
Mayonnaise (1 teaspoon)
Milk, 2% (1 cup)
Nuts, almonds, cashews, mixed (6 nuts)
Nuts, peanuts (10 nuts)
Nuts, pecans, walnuts (4 halves)
Nuts, pistachios (16 nuts)
Oil, cooked (any type) (1 teaspoon)
Olives, black 8 large)
Peanut butter (2 teaspoons)
Salad dressing, regular (2 tablespoon)
Seeds, pumpkin, sesame, sunflower (1 tablespoon)
Shortening (1 tablespoon)
Sour cream (2 tablespoons)


This information has been reviewed and approved by Miranda Y. Ku, MD, MPH
(December 2014).