Right now, this is just me, Vholes, putting together a rough guide to getting enough energy to complete a fast playthrough of the main quest line (I'll assume the goal is a 2-dayer since that's how I play). I'll request some feedback from other notable resetters soon.
Each Day
If you belong to a gang with smugglers, Luxury Food is decent quality, and costs absolutely no energy to obtain. Most of the food can be eaten right away, but keep in mind that truffles, ritzy soda, and black label chocolate give you effects you could save for the right time. Also remember that the rum flask does NOT give energy, and should be avoided if you're trying to generate it.
Day 1
If you can get to the University for your second luxury food shipment, you're doing well. It's often worth it to eat 1 or 2 ancient candybars or other atrocious foods in order to get there.
If you have an unearthly coin, the food from the University shipment might be enough to let you "coinfish", i.e., get the fishing pole on the Docks, flip the coin, equip the pole, and catch a giant pike. Accepting Mikhail's reward and/or killing the gang boss should leave you with enough credits to buy a sushi kit to craft pike sushi. Remember, you can only get the fishing pole after the Fangs have been defeated. This is also a good time to multitask if you're hunting for the crate of stolen medicines, Midgard cap, and/or warehouse security badge. Be careful not to leave your fishing pole equipped after the fish is caught - your fishing skill will be so low it's a waste of time to fish after the pike.
Stockpile any hunger and body remaining for tomorrow.
Day 2
"Coinfishing" should be possible today and each subsequent day. See above for a description.
Purchase a chemistry kit, and read chemistry papers until you learn the recipe for making caffeine powder out of horrible black coffee. The coffee can be obtained at the Midgard Biotech coffee machine whenever you get there.