Duggar Girls In Crisis: Eating Disorders, 'Physical Desire' & Other Sins REVEALED In New Tell-All Book

With 19 Kids And Counting, the Duggar family has no shortage of personalities -- and issues.

RadarOnline.com has learned that eldest daughters Jana, Jill, Jessa and Jinger are opening up for the first time about their darkest secrets in a new book, Growing Up Duggar. And their stories of bulimia, sexual frustration, angry outbursts and more make it clear that their reality is a lot different from the one you see on TV.

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"All of us have gone through times when we've felt we need to lose weight," they admit. "…We've found that most of us older Duggars have a tendency to gain weight."

Mom Michelle has helped out, they claim, by offering healthy fruits and vegetables and offering them diet tips. But her attitude towards food and body image wasn't always so healthy. She recently admitted to struggling with bulimia, and the girls describe for the first time her deadly battle with the disease.

Fifteen-year-old Michelle "had a sweet personality and winsome ways that made her one of the most popular girls in her high school," they write. "Thin and beautiful, she was a girl every guy probably wished he could date. But Mom told us those characteristics were all just outward appearances."

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On the inside, she "battled intense insecurity, destructive thoughts and emotions, and al longing for 'real happiness. …And when she looked in the mirror, she didn't like what she saw …"

It was only finding God -- and her husband-to-be Jim Bob-- that saved her, they claim.

But when it comes to finding their own Princes Charming, the Duggar girls say they are proceeding with lots of caution.

They admit, "God has created us to have a natural physical desire toward men. When these feelings arise, we thank God for making us 'normal.' … But during our single years, this physical attraction, if not carefully controlled, can also be one of the biggest sources of temptation and struggles."

To avoid that, they say, they avoid spending time alone with guys because "it's easy to put yourself into physical and moral danger and give into those emotions or sensual thoughts that promise pleasant, but only temporary, fulfillment."

And even when they're alone, they say, they are able to "control what's going on in our minds. By censoring our thoughts through the filter of God's word, we will be able to recant any wrong thoughts or temptations that try to sneak in, and throw out the lies the devil is sending our way."

But as they start "courting" future husbands, as Jessa recently has begun to do, they can't exactly look to their parents' example in that regard. Jim Bob and Michelle have admitted they went too far too fast physically before marriage, and hope their daughters don't follow in their footsteps.

Their parents also aren't the best example when it comes to anger, the girls admit.

"Not that he has a major anger problem," they write, but Jim Bob has struggled with his temper after growing up with an angry dad. "Over the years he has gotten much better about not letting things stir up a spirit of anger in him," the 19 Kids and Counting stars write, "but he would be the first to admit he has not completely conquered it."

Michelle has admitted to having issues with anger as well, and the girls reveal that she's found a unique way of dealing with it -- by whispering. "When Mom whispers," they claim, "most likely someone is in trouble."

For more on the weird and wonderful world of the Duggars, through the eldest girls' eyes, stay tuned to Radar!