* Nine subjects with CF will be recruited to complete the MBT on two separate occasions, with different doses of pancreatic enzymes
* At each MBT visit, subjects will receive a specific enzyme dose just before they drink the test meal (shake)
* Fat absorption is maximized when the enzymes are taken with the shake.
* If subjects usually receive brands of pancreatic enzymes different from Creon, their dose will be converted to an equivalent dose of Creon 20 for the study.
Prior to each study visit all subjects will be required to:
* Eat their usual diet for 2 days prior to MBT
* Refrain from consuming alcohol or dairy products for 24 hours prior to MBT
* Refrain from non-routine physical exercise for 20 hours prior to MBT
* Adhere to a 12-hour fast prior to MBT (from 8 PM previous night)
* Can drink water from 8:00 PM on the night before the test to 2:00 AM on the day of the test
* At visits 1 and 2, blood samples will be obtained at hourly intervals over a period of eight hours.
* Samples will be analyzed for PA, HA and Triglyceride concentrations.
* Patients will be permitted to ingest non-caloric and non-caffeinated beverages.
* At hour 6, patients will be provided 1000 Kcal, low fat (12 grams of fat) lunch meal.
