Irritable Bowel Syndrome Message Boards | Fruits, veggies, SF, IF, peel, chop, cook (long post)

This is pretty much in response to the Q&A in this thread. I was finding it very difficult to navigate the different streams of conversation, so I decided to break this out into a new thread.

I had already pretty much put these thoughts together before Heather's last post in the existing thread, so I decided to go ahead and post it. I hope this helps clarify things, rather than muddying the waters more.

I came up with this based on a close reading of what Heather has to say about the various fruits and vegetables, a little Web research, and some common sense. If anyone see something I've gotten wrong, please say so.

Here's how I think about soluble fiber fruits and vegetables versus insoluble fiber fruits and vegetables. It's a continuum. Most fruits and vegetables have some SF and some IF. In general, peelable fruits and vegetables have more IF in their peel than in their innards.

Let's look at specifics.

Here are the foods Heather identifies as Soluble Fiber:

Rice; Pasta and noodles; Oatmeal; Barley; Fresh white breads; Rice cereals; Flour tortillas; Soy; Quinoa; and Corn meal - these are not fruits and vegetables where the issue of peeling arises.

Applesauce - the issue of peeling does not arise; it's all soluble fiber

Avocados; Bananas; Mangoes; and Papayas - you always peel these; the insides are soluble fiber

Chestnuts - you don't eat the shell; the insides are soluble fiber

Mushrooms - you eat the whole thing; all soluble fiber

Pumpkins - you don't eat the skin/shell; the insides are soluble fiber; the seeds are insoluble fiber

Squash, zucchini and yellow - the insides are soluble fiber; the skins are insoluble fiber

Squash, all others (e.g., acorn, butternut, spaghetti) - you don't eat the skin/shell; the insides are soluble fiber

Turnips - the insides are soluble fiber; the skins are almost certainly insoluble fiber

Carrots - the whole thing is soluble fiber; you can peel them if you want, but it's not necessary

Parsnips - just like carrots

Rutabagas - you don't eat the skin; the inside is soluble fiber

Beets and rutabagas - I don't eat these, but from what I can tell, you don't eat the skin; the insides are soluble fiber

Potatoes - the insides are soluble fiber; the skins are insoluble fiber

Yams, Sweet potatoes - the insides are soluble fiber; the skins are insoluble fiber

Other fruits and vegetables are more IF than SF. Chopping and cooking does NOT change the IF to SF. It just makes it easier for your digestive tract to break the food down, so it doesn't have to work as hard. Digestion is the process of breaking down the bonds that hold food together. Chopping breaks these bonds down mechanically, cooking breaks them down chemically. These two processes do some of the work for your digestive system - chopping is like chewing, cooking is like digestion. Even after chopping and cooking, however, you are still left with IF, albeit partially "digested" for you.

Based on what I'm seeing in Heather's list of Insoluble Fiber, here's what I think the deal is with peeling:

If you peel apples, pears, peaches, nectarines, and apricots, you're left with soluble fiber. If you peel and seed eggplant, tomatoes, and cucumbers, you greatly reduce the amount of IF, but there is still some left. If you peel bell peppers, you reduce the amount of IF somewhat.

I found these 2 quotes from the Insoluble Fiber FAQ especially valuable: