Youtuber T-Ronix has done some impressive things in the world of Fallout. He's completed Fallout 3 without healing himself once, and somehow he's even topped that in Fallout 4. Playing through Survival Mode (which essentially kills you in one hit) T-Ronix successfully completes the game without a true death. I say that as he did die one time after a glitch in the game caused him to die after touching a stationary car, so we can't count that.
See the final leg of the run here, and if you want to indulge in the several hour full version...check it out on his channel. Thanks to Eurogamer for showing this off.