With a Pisces ASC I can sometimes become a little too couch-potato-ee and therefore, on occasion, a couple of Diet Cokes will be consumed to fight the stupor.
It's a little stimulative kick and I find it works...but I could never indulge on a daily basis as it would make me sick.
However, I have a friend who consumes a liter of Diet Coke every morning to start her day. It wakes her up. She does not drink coffee.
Food and beverage, diet and digestion, are ruled by Moon and Venus. In my friend's case, she has Venus square Uranus (in Cancer) and Moon parallel Uranus by declination...the need for stimulation and a craving to ingest soda to provide instant energy...and a reluctance to prepare, sit and savour a home-cooked meal on a regular basis.
I think Uranus is the key here.
Remember, in the natural horoscope, Uranus-Aquarius (r. 11) inconjuncts Moon-Cancer (r. 4) so there is a natural incompatibility here between eating at home, slowly, with family; and a peripatetic lifestyle of always being on the go and eating out at fast food restaurants or take-out.
People with strong Uranus-Aquarius in their charts will often have this struggle with a poor diet that catches up with them in middle-age. For them, life is full of too many exciting possibilities beyond the home and kitchen. Whatever can be grabbed quickly will do.
Any wonder then, that America, with its Cancer Sun and Aquarius Moon, is ground zero for this type of conflict.