Cooking Light had an article recently that compared remaining fats in different meats before and after cooking. The calorie and fat difference between a breast cooked skinless and one cooked skin on/removed before eating was negligible, but the moistness content was wide-apart. Moral of the story? Cook skin on, then remove. You may choose to re-purpose that skin to fry.
What I found more interesting was how much fat was rendered from the different ground beefs. Our corner grocery store has Wacky Wednesday deals. Each week they offer 80/85/90% lean ground beef for (this week) $3.29/$3.79/$4.29 per pound. When making spaghetti sauce, I usually buy the 80% lean since I drain off the fat. When cooking light tested the waste-to-meat ratio of the different fat content beefs, it turns out there is WAY more waste from the "cheaper" meat than is worth it. For my $$ and time, I'll be making the sauce with the 90% beef.
I've looked all over the web for the chart I saw in Cooking Light. No luck. If I run across the pages that I pulled out and set aside for future use, I'll post the info somehow.