This isn't my opinion so much as what my research has come up with John. If you eat an orange a day your body may get used to that over time and be okay with it. But the natural way the body works is when you eat your body goes into digestion mode- it actually puts into motion a lot of energy to make the whole digestion system function. It really is a lot of work to put into digesting just one orange a day and seriously probably would not be worth that effort. And it's not like the whole digestion system can just be switched on and off like a light switch, it's a whole industrial process which takes time to start up and run and shut down again.
Then when you stop eating the body actually uses part of the digestion system for other purposes, which it never gets to do while the digestion system is running daily. The body is a whole different organism while fasting, and again this isn't something that can just be switched on and off. If you eat good high quality food I do believe you can train your body to adjust to Intermittent Fasting- such as a day eating then a day fasting- but this is not normal and if the food wasn't high quality starvation could be a real danger.