1. Always Be Prepared
A Level III eater won't be forced to eat crap food or no food because they were "busy" or "out all day". It's simple. They bring their food with them. Eating on the road, on vacation or when busy is no different than eating at home or when you have ample free time.
2. Super Hero Drink Mix
Not Gatorade, not KoolAid...
A mixture of supplements rather. Mix them in a big container to follow #1 (always prepared) and easily have your drink every day. If you say "it's not convenient" or "I always forget" and "I am too busy", then MAKE IT EASIER.
In my Super Hero drink mix:
3. Variety is Key
Yes fish oil rocks and olive is a staple but a Level III will have ALL the best oils. Open my fridge door and you will find hemp, flax, macadamia nut, almond, vegan mixture, fish oil, coconut oil and quality olive oil. And yes I also have and use butter.