The only way to find out is to empirically experiment yourself: Eat/don't a specific thing for some period of time and observe how your being is affected.

The most basic side-effect is that your gut craves what you eat. So if you stop eating it you'll exhibit addiction-like symptoms of really wanting to eat it again. For this reason to get a clear picture you should perform dietary experiments over a long enough period, like a month.

I've done many of these, including eating nothing but banana for a month. Highly enlightening.