Well here’s glimpse at my own prejudices – I read right past the word “fat” several paragraphs back because it struck me as a descriptive adjective.  Then I made it to paragraph 1.065 and the dwarves sing of treading on the fat.  The fat in question seems to be a kitchen supply, such as lard, and reminds me that “fat” is a foodstuff.  Here we go!

• 01.004 They are inclined to be fat
• 01.050 For one thing Bombur was immensely fat
• 01.065 Cut the cloth and tread on the fat!
• 02.046 for a nice bit o’ fat valley mutton like what this is.”
• 02.067 “You’re a fat fool,
• 03.028 “He is too fat to get through key-holes yet!”
• 04.046 said poor Bombur, who was fat,
• 06.078 fat melts, and bones black
• 07.087 He was fat,
• 07.121 and fat again on bread
• 08.026 You should not be so fat.
• 08.033 Bombur slept on with a smile on his fat face,
• 08.084 They’re not as fat as they might be.
• 08.088 With that one of the fat spiders ran along a rope
• 08.096 Old fat spider spinning in a tree!
• 08.096 Old fat spider can’t see me!
• 08.101 you are fat and lazy.
• 08.123 and stabbing at their fat bodies if they came too near.
• 10.015 Poor fat Bombur was asleep or senseless;
• 10.038 and they quickly grew fat
• 11.018 I am too fat for such fly-walks,’
• 12.060 though it was fat enough.
• 15.059 except perhaps old fat Bombur and Fili and Kili.
• 16.010 grumbled the fat dwarf.