Eating only a partial portion of certain foods.

I very often will eat only part of a "serving" of foods. (Half an oz of sunchips) etc..  So I always edit the grams/oz portions when adding it to my food log.

However, I find that a lot of foods don't have that option.
Spaghettios being a regular issue.  I don't want to ignore the spaghettios I eat, but I also don't want to write down that I ate an entire cup full when I usually only eat a large spoonfull.  Is there any way to alter the portion size of certain foods that seem to lack that ability without having to manually enter a new food into the program?

I just put in a decimal of the portion size listed.

So if I ate a fifth of a cup, and the serving size is one cup, I list that I had .2 servings.

Yes that's what I do. But like I said

with some foods, you don't have that option.
Try looking up spaghettios and adding it. There's no way to edit the portion size.

I know what you mean.  I eat partial portions of some items, double or more of others.  I enter these myself but it can be time consuming entering all the nutritional info each time (I like the coach function and being given a good grade for my choices).  I do the math on a calculator to show the actual calorie count.  I hope CC figures out how we can each choose to add our info to their list.  It would be helpful to all of us!  At least they should make it possible for us to save the info we enter ourselves.  CC admins, can you hear?

And again this is an issue.

I want to add that I ate 1 donut hole from Dunkin Donuts.

The only option is 1 serving (3 holes)
Or I can choose 2 or 3 servings. 
The ability to add in my own oz/grams whatever is not there.

Yes I agree. The same with tagged foods that you manually enter. It seems silly to have to re-enter a food just because you choose a different portion.   I hope that one of the programmers can figure a way to fix this soon.

While I absolutely LOVE LOVE LOVE this site, I agree with you on this.  I dislike it when the only option is 1 serving, 2 servings, or 3 servings.  Needs to have an 'OTHER" option so you can enter ounces, if you want.  I have a great digital kitchen scale and sure don't mind weighing, but as igrowviolent said, you don't always have that option.  Great suggestion!