i'm a casual fan of the NFL and i was wondering...?

yes, all NFL linemen are on the hefty side. Very strong and quick for being as stout as they are.

There aren't many famous offensive linemen, but there are a few famous defensive. Mean Joe Greene is probably the most famous. Deacon Jones, Randy White, Reggie White, Lawrence Taylor are the one's I can think of off the top of my head.

Defensive lineman need strength and quickness, while offensive linemen need good footwork and balance to not get run over by the defenders who have momentum built up coming at them.

I think they prefer to be known as "big boned". Yes, all linemen are heavier. They look fat, but most these days are fairly athletic. They run amazingly fast 40 times for being so large.

Orlando Pace is a pretty famous tackle, but his season was just ended by injury. Maybe the most infamous lineman were Tony Mandrich, rock star status out of college until doping testing in the pros ended his advantage, and Conrad Dobler perhaps the nastiest dirtiest lineman to ever play the game. Just my thoughts.

I think OL need better foot work and balance than a DL.

No, they're not all fat. Most aren't. They are large and bulky but their bodyfat is normal.

Famous linemen... Rosie Greer, Deacon Jones, Jim Burt... all defensive linemen. As for offensive linemen, they do go a bit less noticed mostly because they almost never touch the ball (save for centers) and thus their names rarely are uttered. But you can have a famous group of offensive linemen like the Redskins' Hogs.

I think that defensive linemen need to be a bit more athletic, have slightly faster reactions and better peripheral vision. Offensive linemen tend to be a bit more stout, but most are pretty quick on their feet, especially inner linemen.

All linemen are big, usually they have a lot of muscle under the excess fat they do have.

Famous linemen would be people like Russ Grimm or Joe Jacoby, these people don't get a lot of recognition because when an offensive line is great, they will give a nickname to the whole offensive line (Like the Hogs), not just single out one or two players.

The best defensive linemen have speed, players like Dwight Freeney who is fast and agile are needed to "outquick" the offensive linemen. Offensive linemen usually have great upper body strength and can use their hands effectively to shove incoming d-linemen and knock them off balance.

There are many in the medical field that are worried because of the declining health of offensive lineman. The latest being the great Reggie White who died from heart failure due to sleep apnea that was caused by his weight.

Some linemen lose a ton of wt. after they retire due to their poor health. There is a lot of pressure for linemen to be as bulky as possible due to the size and speed of the defensive and offensive players.

The lifespan of linemen compared to the skilled positions is much worse. Hopefully the NFL will get these great athletes to keep their wt. down and for the teams not to be so obsessed with keeping them as huge as they are.

They are what makes the O go round and round! Without them your left with a sacked QB and a Rb with no where to go, and bunch of crying Wr with no catches! MY fave, cant say how famous worldwide he is, but Rayfield Wright from the Dallas Cowboys! Finally got his dues to the HOF! Forgot about the next question...I think overall agility and speed make u a better D lineman. I wouldn't exactly call them all fat, you get your 320lb guy here and there but they are fairly solid people!

They look fat, but they are actually fast and strong and have great footwork....ive seen linemen challenges on tv, and those guys can really move....back in the day, you could be fat and play on the line....now days, you need lots of athletic ability along with size and strength.

no there not all fat