How great that Valerie Bertinelli’s new book, Losing It, made it to number one on the New York Times bestseller list! Why do I care? I had just interviewed this intrepid girl. Here’s the result:

“BE NICE. Don’t lie.”

Those four words sum up Valerie Bertinelli’s philosophy. She delivers them with a characteristic, girlish grin and a broad shrug that conveys: “What — doesn’t that make sense?”

I met Valerie about eight years ago. She was promoting a TV film, one of the dozens she has made since her debut back in the 70’s as the luscious younger daughter of Bonnie Franklin in the series, “One Day at a Time.” Bertinelli wore no makeup, sweats, and looked like a teenager, though she was then well into her thirties. We talked a lot about theater and books, and I came away impressed by her normalcy. She was the least actressy of actresses. We didn’t probe her private life. At that juncture, it seemed a relatively calm pause in her marriage to rocker Eddie Van Halen. I assumed she was a woman who knew how to handle the tough stuff — rock and roll marriages are a hard haul. She talked lovingly of her son, Wolfie. She seemed very much the girl next door — literally. (Except — she was married to Eddie Van Halen, for heavens’ sake!)

Last week I met Valerie again, under very different circumstances. Her marriage had ended, her weight — a constant struggle — had ballooned. She joined the Jenny Craig team, became a spokeswoman, and wrote a book. When she stepped out of the elevator in the Trump Hotel, I was stunned. She looked exactly the same as when we first met. Except — because this was a day of press junkets — she was beautifully dressed and made-up. The figure of her teen-age pin-up years has returned. When I complimented her on her freshness and unchanged appearance, she said with a very bawdy laugh, “Four inches of make-up. That’s the secret. Oh, I can’t wait to get this crap off my face!”

By now the press has picked up on what they consider the hot parts of Valerie’s memoir, Losing It — And Gaining My Life Back One Pound at a Time. Truthfully, none of that stuff came as much of a surprise to me. Yes, she’d been a sort of America’s Sweetheart, a sort of hot sweetheart, but wholesome.

But is it so shocking to learn she had sex as a teenager? Or that during the course of her long and troubled marriage to Eddie Van Halen, she had strayed? (His extra-marital adventures went beyond mere straying.) Are we truly astounded to read that Bertinelli used drugs, especially during the heady first years of her wedlock, before Wolfie came along? As she explains it, “Partying with Ed was my way of trying to fit into his world…he was almost totally nocturnal. If I hadn’t stayed up drinking and doing coke with him…we wouldn’t have seen each other.” (She is even-handed about Ed’s struggles, his creative frustrations, his good and endearing qualities. And that they were just too young and “in-lust” to consider the realities of married life.)

So these bites are what make the news. But the heart and soul of her book is a long painful tale of body obsession, insecurity, a life spent judging the good and bad times by what her scales and her mirror told her. Now she can look back ruefully and concede, “I was fine, a typically-sized young woman. What was I worried about?” But for most of her life, she was tormented by what she expected of herself, based on the expectations of others.

A defining moment came early on, before she reached puberty. One of her elementary school teachers passed Valerie and some girlfriends. He stopped, chatted briefly and then patted Valerie’s tummy, “better watch that,” he said, leaving a little girl with a great big problem.

I asked Valerie if she ever thought how her life might have been different, had that incident never occurred?

“Well, I have thought about it. I suppose it might have been different, or maybe it would have been somebody else, another situation. I never felt normal again, but maybe there was something in me, waiting to be triggered. I don’t regret my life. It’s been fabulous in a lot of ways and I have my wonderful son. I wish it hadn’t taken me forty-seven years to figure myself out.” Then she paused. “Of course, I haven’t. That’s the point of the book. I still don’t know why we do what we do. Why are we so hard on ourselves.? Women especially. I’m such an average woman, my problems are so not unusual. But I didn’t realize that for a long time. I wrote the book for other women, and not even as some, ‘see how I triumphed’ manifesto, because, who can see the future? But I wanted to share my experience. It’s such a cliché — maybe it’ll help one girl, one woman.”

Valerie credits her parents for reigning her in, during the hot days of her early stardom. “I thank God every day they kept at me, didn’t let me get away with what I naturally thought I should get away with. I had freedom, after a certain point, but never enough to go hog wild.”

I mention the “diary incident” in the book (Valerie’s mom discovered and read her diary, which revealed that her 17-year-old daughter was, well — a woman.) “Oh, oh! Yes, well, I was just outraged and carried on and locked myself in my room, and screamed, ‘I hate you!’ Very dramatic. The funny thing is, when I told my mom I was putting it in, and she read it, she said, “Oh, but honey, you never said you hated me.’ She wouldn’t accept that memory, which is rather sweet.”

Valerie gives a wry grimace, “Of course I can’t get on and check Wolfie’s iPhone, he’s got it locked off. Listen, you do your best, you just can’t stop your children from making some mistakes. You hope they are not life-altering and that they come out of their adolescence okay. And, in my case, which wasn’t normal, because I was an actress, I benefited from my parents not being invested in my career, they couldn’t have cared less. They didn’t live off me. I did not have that pressure.”

This led to lively talk about Britney, Lindsay, paparazzi, TMZ, the cult of celebrity. Valerie was on target, but wary of being “too judgmental…my worst trait. I have to watch myself. I’ve never walked a mile in their shoes.”

Sitting in on our brief chat —Valerie was pulled away to tape at CNN after about 20 minutes — was her guy, Tom Vitale. They are great together; he has seen her through thick and thin, literally. We all laughed over an episode in Valerie’s book when, after her divorce from Ed, she briefly flirted with the idea of Kabbalah — she dated a man who was really into it. But when they made love, Valerie always turned out the lights, as was her lifelong habit. “The Kabbalah might be all about bringing in the light,” she explained to her lover, “but it says nothing about the bedroom!”

Tom took her hand. She said, “I don’t do that any more, no need to.” He replied, “Honey there was never a need to.”

Valerie says she went through a lot of her life with blinders on. They’re gone now, and she’s got a man who won’t ever let her wear them again.