I think this is kind of justifying after-the-fact, I don't believe she really WANTS to be fat to repel society.
Obesity is so complex. It's really more of a toxic relationship with food than it is "just eating too much", pretty much every manner and any connection to food is toxic. I have a father who is obese, and I don't even like to hear food being mentioned about in the slightest context. He also has some of the strictest eating habits I've ever encountered. Literally, every dimension of food that is positive is made a negative, and every already existing negative is accentuated. No one in my family delights in food in any way in his presence (talking, eating, food network shows, etc. These are all exhausting.)
Her weight is not to shield herself from predatory men; her weight is probably because she hasn't seen a therapist or gotten help, truly. There's another aspect to obesity, and that is delusion. The outside world is almost entirely a delusion that only slightly has to do with food. Think alcoholism and the alcoholic: I think AA has a saying about alcoholism only being part of the problem. Not to mention, alcoholics tend to think "I can control my drinking, I just started drinking heavily because of ______. (I developed a toxic relationship with alcohol because ______. is how is actually should be stated)".
Finally, I'd like to say that I think there's a suicidal (and I don't mean it metaphorically, I mean actually a suicidal tendency) that lurks behind obesity, and I've seen it with my father. He also associates with people who have this, and I don't know how to describe it. For example, he hired a kid who immediately disturbed me with the way he acted, his mannerisms, etc. Came into work constantly limping, black eyes. 27 years old but always having "accidents", always in "pain". And only ''typically' a thrill-seeker. But he got a motorcycle, and was running it at 140 mph sometimes on the interstate, and I knew he was trying to get in a wreck but not consciously trying to get in a wreck. He did get in a wreck, in 2 weeks of buying it, and actually seemed placid about having 0'ed out his bank account, 0'ed out his credit, injured himself, etc. I see this same instinct, it's not even riding a bike in a thrilling way to be a thrillseeker, like obesity, there's a drive to suicide through eating.
The article writer didn't have obesity or addiction issues in her family or she wouldn't have masqueraded such a twisted disease as a statement. When you have people like this in your family, they tell you things like this all the time "My obesity is feminism", but it's exhausting, it's sad, these conversations happen around food so often they make you tired.
I'm pretty far left, I'll even admit feminism has alot of good qualities, and I like a few writers and editors for the atlantic. But this magazine has increasingly published disturbing, SJW slop (see the Dunesberry guy's article on Charlie Hebdo, it's slop)