Hi, I'm the mom of a child with CF who is 9 years old. I'm also working on getting my certification as a nutrition therapist (but have been studying nutrition for over 20 years).
Generally speaking, CF enzymes are prescribed based on several factors, but most importantly your weight, and so your doctor will prescribe your dose based only on the number of lipase units per pill per meal. Lipase is the enzyme that digests fat. All CF enzymes (that I'm aware of) do also contain a variety of other enzymes, including protease (to digest protein), amylase (to digest carbohydrates), and many others (there are many different digestive enzymes produced by the body, so there are also many types of enzymes in our CF pills). But again, they are prescribed based on how much fat-digesting enzymes are in each pill. SO the digestion of fat is often what doctors focus on. However, just because it's the only part of food they talk about, it's not the only part of food you need help digesting. You wouldn't generally want to get too high a dose of lipase units per kg of body weight or you'd be at risk of developing colonic strictures, etc. So, pills are dosed and prescribed based on lipase units, but to be sure, the other enzymes in each pill are necessary to aid your body in digesting all parts of food, including protein and carbohydrates.
The reason people with CF can eat fruits and vegetables without taking supplemental enzymes is because the body naturally delivers amylase, the carbohydrate digesting enzyme, directly into the small intestine. Lipase and protease come from the pancreas and have to get into the small intestine via the tiny little pancreatic duct that is often blocked because of the thick mucus of CF. Maybe there are some people who still need to take enzymes in order to digest fruits and vegetables (so don't take this as medical advice, by any means!)
I hope this helps to clarify what the enzymes are all about.
