I ate too much pie on Thanksgiving. I should probably confess that I’m writing this column a few days before Thanksgiving, and I’m not even sure if we’re having pie for the holiday, but no matter: I’m saying this because it’s what I’m supposed to say. It’s what we’re all supposed to say as we grasp our bellies and recount the story of the one day a year in America during which gluttony — real or perceived — is not only socially acceptable but actively encouraged. Count your blessings, we are told; you can count your calories tomorrow.

But what’s “too much” pie? Three pieces? Two? One? And what, for that matter, is “fat” or “too fat” or even “obese”? Is it a number on a scale? A number on a scale juxtaposed with height, age and other measurements? Or are health and weight more states of mind, subject to the arbitrary whims and objectives of the government, medical community, society or whatever micro-culture we happen to inhabit?

It’s unlikely that many of us will take the time to consider these questions. Because after Thanksgiving, I and many other Americans, particularly American women, will go back to our regularly scheduled programming of self-loathing, the Sturm und Drang of want and need and guilt and anxiety and obsession over food and weight that has been instilled in us since, well, since as early as we can remember. Some of us will go to the gym. Others will dispassionately pick at spinach salads and cans of tuna fish or egg-white omelets. Even those of us mentally healthy — or determined — enough to reject morning-after self-defenestration will be bombarded with messages on morning television shows, in newspaper lifestyle sections and around office water coolers on how to “survive the holidays” or “prevent the holiday heavies.” These are the soundtracks of the season . . . and of our lives.

Last month, filmmaker Darryl Roberts released his second documentary film, a follow-up to his first, 2009’s “America the Beautiful,” which lambasted the not-so-uniquely American obsession with beauty. His new film, “America the Beautiful Part II: The Thin Commandments,” is a more focused exploration of some of the issues raised in his first, namely this country’s preoccupation with thinness. Roberts’ film is a bit Spurlockian in execution, which is to say that it owes a bit to the 2004 breakout film “Supersize Me,” in which West Virginia native Morgan Spurlock ate fast food for a month and then documented the ill effects on his health. But “The Thin Commandments” is about a lot more than just Roberts’ personal journey toward a healthier lifestyle or the problems with metrics such as the Body Mass Index (BMI): It’s an indictment of the effect that the American obsession with weight and the influence of the get-thin-quick-industrial complex has had on the psyches of American women.

This isn’t to say that only women suffer from cultural prohibitions against weight gain and obesity. Pressure to look a certain way has begun to shift to men, says Roberts, whose film includes footage of a group of mostly Caucasian middle-school boys recovering from a variety of eating disorders. (“I wanted girls to like me,” says one.) But the main characters, the people at the heart of the film — the longtime anorexic with the failing marriage, the 20-something exercise addict and wannabe movie star, the middle-aged bariatric surgery patient, the professional dance instructor, the former model — are all female. “Let’s be honest,” says Roberts. “This is part of the fabric of women’s lives.”

Erin Nieto is a former English instructor, occasional art appraiser and mom of two young boys. She’s also a sort of accidental body-acceptance activist, whose blog, Cheap Is Expensive, started earlier this year, resulted in the publication of her first book (with photographer Sheila Daniels), “How Much Do You Weigh?” Published by the small Illinois press Squidbaby, the book features the photos of 25 people of different ages, body types and ethnicities. The only text accompanying the photos are numbers, which denote each individual’s weight. All of the photos are of women.

As with Roberts’ film, this focus on the female experience is no accident. As Nieto explains, although men are subject to some of the same sorts of cultural standards as women, women “seem to more easily internalize these messages as something they are supposed to reflect in order to feel validated and worthy of love and happiness.” (Nieto adds that the men in her life, including her husband, didn’t really get the point of the book at first. Women, on the other hand, reacted with immediate enthusiasm.)

The effect of “How Much Do You Weigh?” in addition to confronting the taboo against publicly announcing/broadcasting the particulars of one’s weight, is that it recalibrates our ideas of what certain numbers on the scale are supposed to look like. If 180 pounds sounds “fat” in theory, it doesn’t necessarily look it in reality, which makes the whole enterprise of weight measurement — and, by extension, BMI — rather meaningless. “People come away very surprised by the numbers,” says Nieto, who adds that she did not include height or age in order to discourage readers from comparing themselves too closely and playing into a cycle of shame. “That was really my aim, just to point an arrow right at that taboo, because its existence not only doesn’t serve women, but it makes us vulnerable to the multitude of pitches we get from the diet industry that disconnect ourselves from our own bodies.”

Late last week, I was riding north on an Indiana interstate when word came over the radio that Congress had declared pizza a vegetable. (Turns out that that wasn’t exactly true.) “That’s great!” I exclaimed to my friend Kate and her husband, who were driving me from Louisville to Chicago, where we would splurge on a cheese and sausage-stuffed pie from a famed Windy City pizzeria called Giordano’s. “Now I won’t feel guilty about tonight’s dinner.”

A few minutes later, Kate — co-author of 2009’s “Lessons From the Fat-o-sphere: Quit Dieting and Declare a Truce With Your Body” — groaned from the back seat. Reading the news on her smartphone, she had just come across a story on a Wisconsin couple arrested on charges of felony child neglect after starving their 14-month-old baby girl because they feared she would get fat. The father, a 35-year-old who was released on bail and ordered to have no contact with the child, told authorities he didn’t want obese children. I gasped and muttered obscenities under my breath.

Those stories, or rather, my reaction to them, helped underscore the complexity and dysfunction of America’s relationship with food: The guilt and shame we feel when enjoying delicious food, and the ways those feelings of guilt and shame make us — and those around us — literally sick. We cannot, it seems, have our pie and eat it, too.

When Jen Shroyer, the Sacramento-area anorexic featured in “The Thin Commandments,” first appeared on-screen in a tight white tee, I winced. Shroyer began dieting as a teen, using Slim-Fast and other calorie-restricting products to emulate Kate Moss and the other waiflike models so popular in the late ’90s. Shroyer’s facial features were drawn and haggard, and her skin and hair looked brittle and dry. It was difficult to tell if she was 25 or 45. But her arms? I’m ashamed to say this, but my initial reaction was that her arms — defined and sinewy and devoid of any body fat — looked sort of amazing. Some habits — even those we thought we were above indulging in — die hard.

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Anna Holmes is a contributing columnist for The Washington Post’s Style section. She is the founder of Jezebel.com.