Credit: Perry Hagopian/Us Weekly

At 115 pounds, Bethenny Frankel has built a hugely successful line of healthy lifestyle products aptly titled SkinnyGirl. And yet the 5-foot-6 reality star maintains an everything-in-moderation, guilt-free approach to eating.

But for the new mom -- she has ten-month-old daughter Bryn with sales exec hubby Jason Hoppy, 39 -- giving up the guilt was a lifelong battle.

In the new issue of Us Weekly, the Bethenny Ever After star, 40, opens up about the obsession with dieting, which first started at age eight -- when her mom sent her to a New York obesity clinic -- and continued well into her thirties.

"I spent my entire life being obsessed with dieting," she tells this week's issue (on stands now). "Bingeing and then fasting or starving. Forbidding everything. That's how I used to be: up and down 5 pounds every single day, to the extremes. My metabolism was totally wrecked."

Among the "5,000 diets" Frankel tried: Atkins, the Scarsdale diet, the Beverly Hills diet, and the cabbage-soup diet.

"I would go buy magazines just to see what the new diet was and rip it out," admits the star, who also battled an addiction to exercise.

For more on Frankel's lifelong struggle -- including which casting director told her to lose 15 pounds, and how she finally broke free from her diet demons -- pick up the new issue of Us Weekly, out now.