@ Senpai - I try to make as much as everything realistically. Still, there are some things that need to be faked or the story hits a block. Why do you think I removed his sniper rifle and his ability to fight IS units? Because even the mantra can't cover how unrealistic that would be. He basically went to "Fighting Laura's IS near head on" to "Getting curbstomped by a barely trying Arachne".
Most of the unrealistic stuff is rule of funny or not important enough to the plot to seriously affect the story. His diet is still a curbed due to his lifestyle. besides, do we ever find out why Cecilia's food tastes bad? It's probable she just put in the wrong ingredients rather than it being toxic. Rations taste like shit, but are healthy enough to sustain soldiers. I liken her food to rations