I can honestly say that one of the best things to increase my energy has been turnip greens.
I'm sure other greens would work (collards etc)
I have had 2 occasions where I thought I just couldn't go on with it all because I was SOOO tired--body and mind were BOTH tired...no other way to explain it. I ate turnip greens and cornbread for 2 meals (lunch and dinner) and I swear the next day I was re-energized!
It is my new diet plan--have greens at least 2x a week!
I know greens have lots of iron and vit K...and lots of other good stuff
I make it by buying the frozen bags, just covering with water--throw in a couple slices of bacon--bring to boiling--boil for 3-5 min, then turn down to low and let simmer for like 30 min...you could then just leave them hot on the stove for a while until you're ready to eat. I usually eat my fill, then put the whole pot in the fridge--then take them out when I wanna eat again, and reboil...
I usually eat them with Jiffy cornbread muffins and butter...yum!