Hey, so I feel like I should know this, but I have to ask. Does anybody here eat grapefruit? I only ask because I am curios about serving sizes and calories. I remember that a serving size of fruit is medium, about the size of a baseball...but when the fruit has the peel that is unedible does that size include the peel or not? If that doesn't make sense, I'm sorry. But I am curios because am I thinking of making grapefruit a regular part of my breakfast. Thank you all.

Try this link to calorie counter dot com -
http://www.thecaloriecounter.com/Foo...9111/Food.aspx

I would think that the peel would only be counted when it is edible (as with apples, potatoes, etc.)

No you do not count the peel.

If you are going by diabetic/dietetic exchanges, it is 1/2 of it or about 11 oz.

http://www.mayoclinic.com/health/diabetes-diet/da00070

HTH!
A.