I see recommendations across the web for anywhere from 20 to 38 grams of daily fiber intake, depending on your demographic. Now, I'm a big fan of fiber and how it helps digestion. But looking at the numbers, I'm skeptical about the feasibility of such high daily fiber intake without supplements like Metamucil.
After searching around, it looks like I'm not alone, either. No matter the fiber-related topic I Google for, the dominant result is pages talking about "how to get enough fiber." Take this one for example, where meeting the daily recommendation requires 3 full meals and 3 between-meal snacks composed entirely of foods specifically chosen for their extremely high fiber content.
If it's so difficult for anyone to reach the recommended fiber intake, it begs the question "Why is the recommended intake so high?" I find it hard to believe that humans have ever regularly been able to meet the current recommendation, aside from cultures where beans are the dominant food.
So what's the basis for current recommendations?