These days Stephanie Pratt looks like a shell of her former self – but unlike most Tinseltowners who are quick say they popped the pounds with “diet & exercise,” the 23-year-old said being down in the dumps lead to a dramatic weight loss.

“It was 6 months of hating life! It was a great secret,” she told Tarts at a recent Hollywood bash when we asked how she lost so much weight. “I got backstabbed by half of my friends, and people stopped looking at me as a friend and more of a commodity and what they could get in the end. I am a very sensitive person to a fault, and I've never been mean to anyone and I kept on thinking, ‘What's wrong with me that makes these people treat me like this? What did I do to attract this?’”

And according to New York nutritionist and founder of SkinnyandtheCity.com Tanya Zuckerbrot, MS, RD Pratt’s now scary skinny body isn’t exactly healthy and she estimates the reality starlet has probably gone from 140 pounds to 112 in the last four-five months.

Click to see Pratt in July

Click to see Pratt in November

“For 5’7, her weight should be 135 plus or minus ten percent. She definitely looks underweight. The problem with losing so much weight so quickly is that your body is starved of key nutrients, and muscle wasting occurs. Muscle wasting is so detrimental to a person's health because the heart is a muscle, breaking down the muscles of your heart leads to heart attack, stroke and death,” Zuckerbrot (who does not treat Pratt explained. “Stephanie Pratt has the ability to be a positive role model to young girls. She should focus on representing realistic and achievable goals that girls can emulate. Currently Stephanie is underweight yet still leads a glamorous life, this sends a message to young girls that skin and bones equals fame and fortune. Stephanie needs to take control of her life and follow a healthy and consistent eating plan with at least three regular meals and one snack. Stephanie needs to gain anywhere between 10-15 pounds.”

And even though Miss Pratt is certainly no angel, she wants to make sure you know that she’s nothing like her even more infamous brother, Spencer.

“The biggest misconception is that I’m like my brother, but I’m not. I’m much more sensitive, mellow and quiet,” Pratt explained.

Speaking of siblings, even Spencer’s sister-in-law Heidi Montag made a point of disassociating herself from the cheesy couple.

“People confuse me with my sister all the time,” Holly said. “People are like ‘Heidi! Why are you married to that douche bag?’ and I'm like, ‘That's my sister you're thinking of! I don't know really what to say!’”