Thanks to Courtney Trouble, Bitch Please, and tumblr generally, I came across the Thin Privilege Checklist, cited like so:

Thin Privilege Checklist

• I can be sure that people aren’t embarrassed to be seen with me because of the size of my body.

• If I pick up a magazine or watch T.V. I will see bodies that look like mine that aren’t being lampooned, desexualized, or used to signify laziness, ignorance, or lack of self-control.

• When I talk about the size of my body I can be certain that few other people will hope they are never the same size.

• I do not have to be afraid that when I talk to my friends or family they will mention the size of my body in a critical manner, or suggest unsolicited diet products and exercise programs.

• I will not be accused of being emotionally troubled or in psychological denial because of the size of my body.

• I can go home from meetings, classes, and conversations and not feel excluded, fearful, attacked, isolated, outnumbered, unheard, held at a distance, stereotyped, or feared because of the size of my body.

• I never have to speak for size acceptance as a movement. My thoughts about my body can be my own with no need for political alliance relative to size.

• I can be sure that when I go to a class, or movie, or restaurant that I will find a place to sit in which I am relatively comfortable.

• I don’t have to worry that if I am talking about feeling of sexual attraction people are repelled or disgusted by the size of my body. People can imagine me in sexual circumstances.

• People won’t ask me why I don’t change the size of my body.

• My masculinity or femininity will not be challenged because of the size of my body.

• I can be sure that if I need medical or legal help my size will not work against me.

• I am not identified by the size of my body.

• I can walk in public with my significant other and not have people double take or stare.

• I can go for months without thinking about or being spoken to about the size of my body.

• I am not grouped because of the size of my body.

• I will never have to sit quietly and listen while other people talk about the ways in which they avoid being my size.

• I don’t have to worry that won’t be hired for a job that I can do because of the size of my body.

When I saw this, I had an immediate "hm". I like the idea of this, but I think that women who are really slender get a lot of shit too- actually, I don’t think, I know. 
Ones I contest:

-I do not have to be afraid that when I talk to my friends or family they will mention the size of my body in a critical manner.

-I will not be accused of being emotionally troubled or in psychological denial because of the size of my body.

-I don’t have to worry that if I am talking about feeling of sexual attraction people are repelled or disgusted by the size of my body. People can imagine me in sexual circumstances.

-My masculinity or femininity will not be challenged because of the size of my body.

-I can go for months without thinking about or being spoken to about the size of my body.

I had a girlfriend once who was naturally very slender. People would say that they liked women who were “real women”- ones who had curves, like me, not small-breasted and narrow-hipped, like her. I would hear people say loudly how they couldn’t imagine sex with a skinny girl, they were all bones. People would be very concerned that she didn’t eat enough or not a balanced diet. I watched her feel crushed under the weight of people worrying that she’d never be able to bear a child, watched her self-esteem waver when people scornfully said how slender women were too boyish for them. And the people who spoke with the most vitriol were often women who considered themselves feminists.

Now, to be fair, I looked at the original source, which says (unedited):

Every year on Gay Pride weekend I like to this article based on the work that Peggy Mc Intosh did on white privilege. For a variety of reasons I thought about it today. I'd like to read something like it from my average sized friends. I'm not really the person to write it. But I know that for many of my averaged sized friends the idea of fat as a political identity is new. So I'm just going to write what I wish I could read.

Everyday as an average sized person ...

I'm glad the original recognizes that this is about what's seen as the average or perhaps the ideal body, vs just thin people.

FUCK THAT.