"Cucumber, with peel, raw" vs. "cucumber, raw"
 

100 gram serving:

Cucumber, with peel, raw Cucumber, raw
Carbohydrate 3.6 2.2
Dietary Fibre 0.5 0.7

How can there possibly be *less* fibre in peeled cucumber?

I think most of the fiber is in the peel. I believe that's also true for something like a baked potato, although I guess it would have to depend on the size of the potato! Peelings are fibrous. So, this may be a mistake in the database and yet... it occurs in another database I checked.

Did you mean 'less fiber in unpeeled cucumber'?

I looked at another website that has an extensive database - and it reported the same strange results. It had 0 grams fiber for cucumber, raw, with peel, and 1 gram for the same amount (100 grams) raw, peeled. Strange. I can't tell you why that would be but maybe it's because they are the same amount - 100 grams - and once you remove the peel, which has a certain weight, the cucumber flesh added to make up the 100 grams has fiber to it that makes the difference. Hard to believe but it's the only thing I can think of.

So maybe it's not a mistake in the database. However, for all practical purposes, it's very little difference between the two, which also points out that maybe the skin of the cucumber is not such a big addition of fiber. Maybe it's just really thin. Thinner than an apple? An apple definitely gives you more fiber when you eat the skin. Then, again, there are varieties of cucumber and they may differ - English seedless, pickling cukes, Kirby, etc. These may also differ from country to country, in variety as well as naming.

Also, it occurs to me that 100 grams is 3.5 oz. Isn't that a pretty small cucumber? Is there such a thing? As you scale down, how possible is it to include skin in something that's rare. I haven't weighed a cuke lately but with water (it's a watery veggie), that has to be pretty small.

I just chose 100 grams to have a consistent base of comparison. That amount would be about 1/4 to 1/3 of most cucumbers I buy. And yes, I meant "less fibre in cucumber with the peel on"... that was an unfortunate typo! :o And after I posted the question, I went to the USDA nutrient database (which I'm sure is what drives this one), and yes, there's the same (presumably erroneous) information. It's not a huge issue for most people, but when you're in the Induction phase of Atkins, it is... :)

Again, thank you for taking the time to post such a thorough and thoughtful response. You rock! ;)