Maintenance Calories-Definate Number or Range?

[Sincer]

For maintenance calories, do situations such as great genetic metabolism, young age metabolism, etc. create a range for the maintenance calories? Example, over six feet tall 19 year old skinny ass friend of mine weighs 130-140 lbs and easily puts down anywhere from 3.5k-5k calories a day in the dirtiest **** food one can imagine(he boasts about having pints of icecream with his lunches). He never gains a pound, has very little or no regular physical activity, and is easily under 12 percent bodyfat. So basically what I'm wondering is for someone like myself with maintenance of 3k, is there a range of about 2,800 to say 3, 200 or larger in which calorie intake has the same overall result on the body due to young age metabolism or being an extreme ecto?

[RedSpikeyThing]

I would say no. You either burn as many calories as you consume, or you don't. There would, however, be a range due to changes in the amount of physical activity you have on a daily basis. So, for example, my maintenance would be higher on days where I walk more.

[malkore]

its considered a narrow range. like, your exact maintenance might be 2000 calories, but if you ate between 1900 and 2100 cals a day so the average was about 2000, you'd maintain your weight.