Quote 91
"I’m not very hungry."
"Come on and eat. You can’t fish and not eat."
"I have," the old man said getting up and taking the newspaper and folding it. Then he started to fold the blanket. (1.92-1.94)
The old man is almost supernatural in his ability to work without food.
Quote 92
The old man drank his coffee slowly. It was all he would have all day and he knew that he should take it. For a long time now eating had bored him and he never carried a lunch. He had a bottle of water in the bow of the skiff and that was all he needed for the day. (2.16)
Eating holds no pleasure for the old man. It is only a means to an end.
Quote 93
He also drank a cup of shark liver oil each day from the big drum in the shack where many of the fishermen kept their gear. It was there for all fishermen who wanted it. Most fishermen hated the taste. But it was no worse than getting up at the hours that they rose and it was very good against all colds and grippes and it was good for the eyes. (2.46)
Eating is an unpleasant but necessary activity for the old man, rather than a pleasure. It is his means to strength.