My new Yellow Lab is between 2-3 years old. I have weighed him and he is between 85-90 lbs. We play fetch every day for about ten minutes and we play tug of war for hours, but besides that he doesn't get much exercise.
So how much should he be eating? I was told about 4 cups of food a day, or is it 4 cups per meal? I have been feeding him 3.5 to 4 cups total per day but he always seems hungry afterward. So can anyone clue me in?
Please help...

many labs always seem hungry.
your dogs are on the large size and mine are 84 lbs each and i feed 1 cup of kibble with a dollap of nonfat yogurt. one of my guys gets raw once a day and i feed him chicken necks and giblets.
i think you may need to cut down or he will become fat.can you feel his ribs easily?

First of all... what are you feeding? 4 cups a day sounds like a lot.

I'm feeding him Costco's kirkland lamb rice and vegetable super premium adult dog food. He's in wonderful shape from what I can tell. I can easily feel his ribs.

Whoa. Four cups a day sounds like a lot to me! Are you and the vet happy with his weight? I agree that you may want to cut back. I find that if I add something- like a few spoonfuls of wet food, my dog seems more satisfied than if I just give him the kibble. He tends to lick the wet food and it takes longer to eat.
With most kibbles, I feed one cup twice a day, plus a bit of canned. (with a high protein food like Orijen, he gets even less.) We walk 4-5 miles, with hills, every day. Hudson is six and a half, but full of energy. He weighs 80 lbs.
And yes, after he eats he looks at me like, "is that all?" But once I put the dish in the sink, he settles and seems fine.

I haven't seen the vet just yet. I just got bailey Friday. He seems to be losing weight actually on his diet now. He eats at 8am and 6pm approx. Each time I give him 2 cups measured out with a one third cup. I'm happy with his weight, I think. I don't think he looks out of shape at all but I have nothing to compare him to.

Being young, 2 cups may be just fine. See what the vet thinks about his weight. All dogs are different, and the only way to really tell if he's where he should be is to actually see and examine the guy. When he gets older you will want to make sure the pounds don't creep up on him.
Congratulations on your adoption, btw. A slightly older pup has advantages, I think.Not only do you know their disposition, but you don't have to deal with house-breaking and separation issues as you often do with tiny pups. Enjoy your big boy!
One thing I would suggest is trying to get him out for a walk at least once a day, even if you only have 30 minutes. They really love it. Mine lives for it, as it's mental stimulation as well as physical, seeing new places and smelling new smells. And it's good for us, too.

I am feeding my 5 month old Golden, Tux, over 4 cups now. I upped it slightly because his ribs became too easy to feel. If a long active life is your goal, you want to keep you dog lean. Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food and exercise adjusted to its individual needs. Here is a link to a good illustrated guide, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx