Read the title and subtitle of this book and you might be forgiven for thinking it another in a long line of memoirs written by cranky moms about their difficult teenage daughters.

Food issues, body image problems, eating anxieties.

We’ve been there before. Haven’t we?

Not in this particular way, we haven’t. Which might in itself be worth a moment of reflection. Have we crossed a line, with the appearance of Dara-Lynn Weiss’ new book, a memoir of dieting? Successful dieting, we should note. But painful, too.

For let’s cut straight to the heart of the matter: this book is about a 7-year-old girl.

The daughter of New York City-based writer Weiss – called “Bea” in the narrative – is an overweight kid at the beginning of the story, which chronicles a year or so in the life of the family (which also includes Weiss’ husband and son). A year spent putting Bea on a diet. A year spent measuring portions, fiddling with scales, doling out low-calorie snacks, in an effort to make Bea weigh what the doctors’ charts said she should.

Weiss made the decision to put Bea, who seems to be a delightful and preternaturally patient child, on a diet after the pediatrician, at her daughter’s 7th birthday checkup, told Weiss that Bea’s 93 pounds (on a 4-foot, 4-inch frame) qualified the girl as “obese” according to the charts used by medical professionals.

That’s where Bea’s – and her family’s – dieting journey began. Weiss made no bones about what she was doing: with her family, with the “nutrition” doctor the family soon employed, and publicly. As Weiss tells it, in the opening chapters of this memoir, it was a decision she knew would raise eyebrows.

“So, sure, I wondered what other moms thought about me,” Weiss writes here, “and how they might judge my actions or inaction. But I was much more concerned about the judgments Bea herself would be subjected to. I wanted to protect her from the problems inherent in growing up as a ‘fat girl.’ I knew people were beginning to view her that way – it was impossible not to – and that their associations with that label were almost always negative.”

Here’s where the waters grow murky. Everyone who has been paying attention the last two decades or so knows that American kids are getting heavier, and thus potentially less healthy. So there is no doubt cause for concern in many parents who are dealing with kids that are struggling with weight problems.

In one sense, Weiss’ tale of her own family’s experience is a brave foray into topics we don’t normally discuss: things like how to limit portions for a little girl who is busy, active, voraciously hungry, and – not unimportantly – keenly observant of the fact that her friends and younger brother are being fed different foods. and more of them, than she is.

This might just be a discussion worth having, right about now.

However. However.

There are things about Weiss’ story, and how it came to be, that make it hard to root for this book. (Which is plain-spoken, almost unvarnished, in its telling; Weiss doesn’t take pains to make herself look particularly good, in much of it, and she is open about the difficulties Bea’s diet caused with her family members, friends, other moms, even her husband. “’I’m done,’ he would say,” she writes of her husband, Jeff. And then she describes her response: “Well, I can’t be done,” I responded at one point. “Someone has to do this.”)

The backstory on “The Heavy” is that it began, last spring, with an essay Weiss wrote for Vogue magazine about her decision to put Bea on a diet. That story – which included photos of Dara-Lynn and her daughter – caused an enormous outcry in many quarters, ranging from popular media websites to mommy blogs to average parents. People felt Weiss was putting Bea on display at a vulnerable point in her life, among other reactions.

In “The Heavy,” though Weiss writes that she learned lessons from that Vogue episode – she expresses regret over allowing Bea to be included in the photographs – she said she is more than ever determined to be at the crux of the national conversation about children and weight.

Her motives might be entirely laudable; who can say? Best to be generous, and assume she wants her story, and Bea’s, to help others. But even with this sort of context for the book, there are passages in “The Heavy” that make for uncomfortable reading – especially for those who are parents.

Weiss writes about how she decided to offer Bea glasses of Diet Coke, in restaurants, when other kids were drinking calorie-filled beverages. She writes about how she gave her daughter 100-calorie packs of cookies and salty snacks to keep her happy with the strict meal plan she was on, rather than organic granola bars and yogurt and hummus, like Bea’s friends were eating. She describes weighing Bea’s jeans, just to prove that the clothes her daughter was wearing for one weigh-in added ounces to her number.

Perhaps the most poignant example involves a scene when Weiss picked her daughter up after school for a visit to a friend’s house. On the way, Weiss offered her daughter an after-school snack, and Bea asked politely for a hot cocoa. The pair went to Starbucks, where Weiss ordered a cocoa for Bea. Then Weiss describes in detail the way she grilled the barista about how many calories were in a kid-sized cocoa.

When he didn’t know – and had to check with others – she fretted and fumed. When the calorie total was produced, and Weiss learned that the drink Bea was sipping also had whipped cream on top, without her instruction, she lost it.

“I grabbed Bea’s cup and pulled the lid off. There, floating on the surface, was a bobbing cloud of whipped cream.”

“‘She can’t have this,’ I said gloomily. I felt upset at the position I was now in because of this counterperson’s careless assumption. Now I had to be the bad guy, because he had made an unauthorized addition to the drink we’d ordered.”

“I knew he thought I was crazy, getting tense over 30 calories’ worth of whipped cream. Well, I rationalized, what if Bea had been lactose-intolerant and he’d added milk to her tea? Why did I not have the same authority to get upset?”

Weiss takes her daughter’s cocoa away, and throws it in the trash. Later, on the subway, she apologizes to Bea, who tells her mom “it’s OK.”

Weiss may have wanted to start a conversation – in Vogue, and now in this memoir – and she may, in ways both intentional and less so, have succeeded.

But after closing “The Heavy,” the mind of this reader kept returning to the figure of 7-year-old Bea, watching forlornly as her prized cocoa landed in the trash.

Heartwrenching – and in more ways, likely, than the author intended.

The Heavy: A Mother,

A Daughter, A Diet

By Dara-Lynn Weiss

Ballantine Books

240 pages, $26

Charity Vogel is a News staff reporter.