I've been playing for about 12 years now, although I have taken 2 years off (non consecutive). I will say that former players tend to get fat fast. Most associate lifting with football...so no more football = no more lifting.
Personally, while I love football, I prob. love lifting more. I'm not sure if I am playing this spring or not...but that doesn't stop me from running, lifting, and generally eating well.
I've played OL, DL, TE and FB. I will say that most OL really like being fat. They love to eat and think that being a certian weight will make them better. Coaches push that bs too. I was told hundreds of times that at 260 (or 250 or 240) that I was too small to play. Then I'd start both ways and make all-Star teams on both sides of the ball.
With the D-Line, the trend seems to be to go with quicker, leaner guys...so hopefully, the OL will adopt similar standards. Honestly, the reason I beat most OLmen is because I'm just plain faster than them...stronger too, even though I weigh less.
Also, the only players I've ever really seen eat well were guys who are not genetically gifted. Position doesn't matter. If a guy is naturally low in bodyfat...they generally eat like shit. Doritos and a pepsi before a game...while I'm sittin there with a protein shake.
Plus, most football coaches push a high-carb pre game meal...and pretty much encourage guys to eat till they barf.