I believe that several years ago I read (probably in print, not on the
web) that carbohydrates were necessary for the absorption of protein,
and also that the maximum amount of protein that could be effectively
absorbed in a single meal was on the order of 30g (probably depends on
size of individual though). The upshot of this is that if one is
trying to gain the benefits of eating protein (e.g., muscle growth or
better recovery and less soreness from exercise) that one cannot
simply eat a meal heavy in protein but lacking in carbs.

I told this to someone who didn't believe it. I wanted to provide a
link or two where they could read some authoritative-sounding sites
that confirmed this. I tried a few quick Google queries, but there are
many, many sites discussing protein and carbs and it is difficult to
restrict to this specific relationship. Still, should be easy with a
bit more sifting to find a few sites that discuss this. Doesn't have
to be the end-all-be-all answer.

Hi,

Thanks for your interesting question!

I have found 3 sites which mention the relationship between
carbohydrates and protein. They all agree that carbohydrates are
important in protein absorption.

The Good Life Fitness Club site has a Word document which states 
"The reason carbohydrates and protein must be combined is that there
is an increase in protein absorption to the muscle when the
carbohydrate is high glycemic. Each alone are inadequate, while
together they become a powerful synergistic formula."
The article is mostly about post exercise drinks though.
As a Word Document:
http://www.goodlife-queensview.com/Articles/post%20exercise.doc
Converted to HTML by Google:
http://216.239.35.100/search?q=cache:7qW-kwnjnEAC:www.goodlife-queensview.com/Articles/post%2520exercise.doc+carbohydrates+%22protein+absorption%22+OR+%22absorption+of+protein%22+increase+OR+increased+synergy+OR+synergistic+facts&hl=en&ie=UTF-8

Mojo Health's site, an article for Cal's personal training clients.
This article is titled "Have you blown your New Year's Resolution
already?" and offers general nutrition tips including "Fibrous
carbohydrates provide fiber which aids in protein absorption as well
as overall gastrointestinal health"
PDF form:
http://www.mojohealth.com/pdf/mojo_jan2002.pdf
Converted to HTML by Google:
http://216.239.53.100/search?q=cache:KTIR2GFcNrcC:www.mojohealth.com/pdf/mojo_jan2002.pdf+carbohydrates+%22protein+absorption%22+OR+%22absorption+of+protein%22+increase+OR+increased+synergy+OR+synergistic+facts&hl=en&ie=UTF-8

Victoria's Vitamins Muscle Growth page: This page doesn't state
directly that carbohydrates should be eaten with protein for increased
absorbtion but does imply the importance. It says
"45 minutes to 1 hour later[after the workout], the post-training meal
would involve a high carbohydrate meal with more protein. About 15 to
25 grams of protein (0.25 g/kg of bodyweight) with 30 to 50 grams of
carbohydrates."
http://www.victoriasvitamins.com/musclegrowth.html

I hope this answers your question and you are happy with these sites.
If not, please request a clarification.

Jenjerina-ga

Search techniques:
I used google with the keywords: carbohydrates "protein absorption" OR
"absorption of protein" increase OR increased synergy OR synergistic

Not quite the same stuff I read somewhere before, but interesting and fast. Thanks.