Q: Why is it that most food labels dont count calories in fiber? Should this be a concern? If you eat say 50 grams of fiber a day that could be 200 calories.

A: Your body for the most part is not able to use fiber for energy, so that's why it is usually not included in calorie count. This is not completely uniform -- some label seem to count fiber in calories, at least partially.

Usually we don't eat that much fiber (though good job if you're getting 50 grams/day!) so it doesn't add up to much one way or another. If you are trying to count calories, then it's fine to count it ether way as long as you are being consistent! Either always count fiber as calories or never count it.