It's amusing to see "WWII" as if the military today doesn't still run on these things. It's more Monster energy drink and vaping these days (I guess still dip for dudes who grew up south of the Mason-Dixon line), but at least in the US Army, the Soldiers are still being fueled by caffeine and nicotine. All the other advice about vitamins and turning off screens and what not kind of goes out the window when you're getting 2 hours of sleep a night for over a year.