Not sure I follow your logic entirely...
gluconeogenesis, aside from a few tweaks, is glycolysis in reverse...there is no way to feed into eachother, as they are one in the same, just opposite.
Ironically, however, the key to getting big, either developmentally or pathologically is not burning energy efficiently — it is backing glycolysis up by mucking the up the flux. That is when things (and by that I mean cells) start getting aggresive phenotypes (i.e., cancerous)...fascinating!
Was a pleasure conversing with you, and welcome to Freerepublic. Hope you enjoy your stay!