Personally, I'm not too willing to rely on caught fish. First, fish is not too calorie dense; a one pound trout yields less than 400 calories. I don't know about you but I don't catch too many one pound trout. Second, the dang fish just don't seem to be hungry on your schedule. They may be feeding during prime hiking time and sulking when you are hungry. Finally, you are not always at fish-able water when you need to be.

In 1954, I hiked the JMT without any resupply stops. At the time I was an immortal teenager so I started with about 20 pounds of food in my pack at Yosemite. I planned on fish to supplement my diet. I finished the last 1/3 of the trail on less than half rations. I couldn't get the fish I needed for the reasons I listed above. Fish can be a welcome treat from standard trail fare but IMO it is not wise to count on having it when you want it.