Credit: Sara Jaye Weiss

What baby weight?

Just three weeks after giving birth to daughter Bryn, Real Housewives of New York's Bethenny Frankel is back to a size-4 swimsuit!

In the new issue of Us Weekly, Frankel, 39, reveals how she's already lost 29 of the 35 pounds she gained while pregnant with Bryn, born May 8.

"I don't believe in diets," says the chef and author of Naturally Thin, who wed Bryn's dad Jason Hoppy March 28.

Frankel stayed active while carrying Bryn, alternating yoga with 45-minute walks three times a week, and practiced portion control with a vegetarian diet.

Still healing since Bryn's C-section birth, the 122-pound star has decreased her walks to 30 minutes and continues to eat low-fat fare. A sample day's menu: a muffin and fruit for breakfast, a veggie sandwich and soup at lunch and BBQ chicken and a half a sweet potato for dinner.

Frankel admits to Us, "I'm still wearing maternity clothes, because they're comfortable." Still, she says, "I"m excited to get into my Louboutins again. No more swollen feet!"