Okay, sorry for the late reply. So there's no way to do the valve and conveyor maze without failing?
Sorry, I meant by how do you go through it without getting so fat. I was able to finally figure the valve puzzle and the broken conveyor (somehow skipped the tile that had the prompt), but you get a lot of fat through the maze (not to mention the catwalks giving a lot by going through them as well as the gas in the sewers being very aggressive in hitting you with more fat).
Then again since an ending isn't available I don't see why to consume every possible food item.