Growling tummy?

No

Nope. That's what I strive for, but if the end of the day is here and I stil lhave some cals remaining and I am wanting a snack then I have one w/out guilt, with or without the tummy growl.

Seems to me that waiting for your stomach to growl before eating is waiting too long. Your body should be alerting you a little sooner that it needs food for energy. The biggest concern about waiting until your starving (which growling tummies may indicate) is that you're more likely to eat more calories than necessary or choose fatty/sugary foods for an instant boost.