Our bodies don’t like to be without food, but we can’t process a lot of calories at one time. If you think about it, you probably spent a third of the day without food when you wake up in the morning. Assuming that you don’t eat right before you go to bed and sleep for 7 or 8 hours, you can easily have gone 8 to 10 hours without ingesting anything.
Breaking your fast tells your body that it is time to get your metabolism moving again. It can handle taking an 8 hour break from food when you are sleeping, but you should never go more than 5 hours without food when you are awake (eating something every 2 to 3 hours is even better). By eating as soon as you wake up (or shortly after you wake up if you can’t eat first thing) your body will speed up your metabolism and you will have an extra few hours of burning fat and calories.
If you just get up and go about your day, you will quickly use up what little energy stores your body still has and will be tired and famished by the time you have lunch. You will then eat more than you need to at lunch time to compensate, and your body will not be able to process all of the calories that you just ingested.
I have never had trouble eating first thing in the morning, thankfully. I tend to eat a small breakfast as soon as I wake up, and then another one an hour or two later. I snack throughout the morning until lunch (carrot sticks, pretzels, peanuts, beef jerky, apple leather, almonds, etc) and then will usually snack throughout the afternoon until dinner. I do not tend to eat much after dinner; I might have a small snack an hour before I go to bed, but then again I might not.