Not sure where you're coming from, but elk are in a high and dry environment. Most people are not in shape to wander the mountains all day long, nor the dry air. You will need lots of liquids and carbs. Stews and soups with plenty of potatos or pasta will perk you up at the end of the day.
Don't forget the aspirin for those altitude headaches. Trail mix with plenty of M & Ms will keep you going during the day.
Take at least 1/2 again as much food as you think you will eat. Better to have too much, than not enough.
Not sure where or when you're hunting elk. But the two most stressed items on the list we give our elk hunters to bring are raingear and boot dryers. Even on dry days the brush is usually soaked in the mornings from dew and fog overnight. Unless of course it is cold enough for snow and frost.