I discovered it! The difference between fat and thin people. It has nothing to do with carbs, calories, or even exercise. In fact, I believe it has less to do with the body than a split-second reflex in the brain.

I figured that our one day when I met my friend Ginny at a café. We slid into the booth and scanned the menus.

“God, I feel fat,” Ginny declared. To illustrate her point, she lifted her bulky sweater and grabbed a hunk of midriff bulging over her jeans. I have to admit, the roll was quite impressive.

“I’ve gained seven pounds,” she admitted. “I’ll get around to it eventually.”

Then Ginny shrugged nonchalantly, as if the world wasn’t ending.

I watched amazed. I was struck by the major difference between us.

Read Confessions of a Shopping Bulimic

Despite her bloat, Ginny is a thin, very attractive person. And she looks, acts, and talks like one. I too am carrying some extra pounds left over from Christmas-cookie time. But unlike Ginny, I am a fat person. Not in the flesh—anyone looking at me would say that I was “normal.” But I’ve been battling my body type since 7th grade, my weight has swung like a pendulum, and I never know what’s going to fit on any given day. So I feel like a fat person most of the time.

So there we sat: one “fat” person and one thin person, experiencing the same plight of being a few pounds over. For me was devastating, for Ginny was no biggie.

“Ginny, what’s the difference between us?” I asked. “We’ve both gained a few pounds. You don’t seem to care, and I can’t stop obsessing about it.”

“The difference is if I gain weight, I don’t beat myself up about it,” she said simply.

Read My French Lesson

And there we have it, ladies: The difference between fat and thin people is not what they’re chewing, but how they talk to themselves after they swallow.

I mostly have very good eating habits. Sometimes I make poor food choices, as do most people. Then I freak out and start counting calories, scheduling gym time and deciding what I’ll eat at every future meal. It’s all so exhausting that I need to eat to get energy just to gear up.

But not Ginny.

“Could you pass the butter?” she says.

Maybe, I think, if I don’t beat myself up about what I eat, I’d relax, eat like a normal person and not think about being “fat.”

I make a radical decision then and there to exercise: exercise self-restraint with my thoughts. The next time I eat something caloric, I’m going to enjoy it. Period. End of story. And then move on and live my life. Let’s see what happens.