[Nicci (OP)]

How long(on average)does it take to digest animal protein such as red meat?
Do different animal proteins digest at different rates?
There are many myths and legends that say it takes four days for meat to pass through the digestive system. This doesn't make sense given the digestive enzymes in the gut. What exactly are "stomach acid" and "digestive enzymes", how are they comprised? It also seems logical that the diet as a whole would influence the rate at which anything digests. ie: if one eats a diet high in fibre, surely digestion of any macronutrient would be more efficient?

[MOD EDIT - please phrase your thread titles as questions, in line with forum policy. Thanks. Chris]

[Chemistry4me]

According to Lisa Cicciarello Andrews, College of Nursing, University of Cincinnati, red meats on average take from 1 to 3 days to be completely digested and eliminated from the body. Red meats take much longer to digest than other foods because of their high protein and fat content.

http://www.weight-loss-center.net/weight-loss-blog/2008/09/truth-about-red-meat-digestion/

[Bored chemist]

Empirical evidence based on drinking a lot of  blue curacao indicates that food stays in my gut for less than 24 hrs.
Since I don't eat a lot of fruit or veg it's reasonable to assume that I get by (at least largely) on the nutrition I glean from meat.
Either I eat a silly ammount of food or the given data is wrong.

[Chemistry4me]

Maybe you just have a very good digestive system.