Do you mind backing that up with some sources/studies? Why is the sequence an old notion? Why is it becoming less accepted? By who?
The body utilizes energy in that sequence (carbs->fats/lipids->protein last) because that is the most efficient sequence of energy. Fats have more energy to expend when broken down, so the body will use that as the secondary source of energy. Protein is the worst source of ENERGY (not muscle building source, pure energy) our body can utilize. Remember that whole cellular respiration portion of bio class? Glycolysis (glucose->pyruvate), formation of acetyl coa from pyruvate, Krebs cycle (acetyl coa loop), then the ETC (electron transport chain, jackpot baby!).
This also ties into the whole aerobic versus anaerobic respiration. Aerobic respiration is utilized and preferred by the body because it has the greatest outcome of produced energy (36atp i believe vs. just 2 for anaerobic). The body will not perform anaerobic respiration if it has oxygen to perform aerobic respiration. Why? Because it's more efficient to perform aerobic, and it will if it can.