CNN — (CNN) -- This year, on the 15th season of NBC's weight-loss show "The Biggest Loser," Rachel Frederickson did exactly what the show producers, the celebrity trainers and the audience asked her to: She lost the most weight.
She lost so much weight, in fact, that many have decided she is now unhealthily thin. Jaws dropped at her final weigh-in. Social media exploded. At 5-foot-4 and 105 pounds, her body mass index is below what the National Institutes of Health considers healthy.
I won't speculate on her health. That's for a doctor to determine, and hopefully she's regularly seeing one. She says she's "never felt this great."
I think I know exactly how Rachel is feeling right now. In a word: intoxicated. And as I also know from experience, that intoxication can be deadly dangerous.
Growing up as a student of classical ballet, I floated in and out of all kinds of unhealthy eating disorders. I experimented with bulimia, starvation, laxatives and diet pills. Dancers knew plenty of terrible tricks. We'd eat carrots and use the bright orange to mark when to stop throwing up before all the nutrients and energy we needed to dance were expended. We ate tissue paper to feel full. We were caffeine addicts --some even snorted it. Many smoked cigarettes and a few did drugs.
Our unhealthy habits at Boston Ballet even led to a "Dateline" investigation in 1997, when a friend and fellow dancer died suddenly at 22. She weighed 93 pounds.
Not only did all of this make for very bad habits, but as an impressionable, insecure and developmentally immature adolescent girl, body issues were ingrained at the worst possible time, and when I was least equipped to deal with them.
My teen years were spent, irrationally, consumed with being too fat. There was depression. There were suicidal thoughts. There was therapy.
When I finally left ballet, I found relief in the normalcy of college. That relief turned to excitement when I found friends -- and boyfriends -- who thought I was pretty great, even without starving myself. And that excitement turned to empowerment when I found a career in writing that turned me on and didn't care what I looked like. I left body issues behind. I knew who I was.
Ironically, all that self-esteem spurred unexpected weight loss. I suddenly dropped 10, 15, 20 pounds without trying. I was eating healthily, working out occasionally, and enjoying my 20s. I'd never been happier. And then it happened.
The compliments, the attention, the looks on friends' faces who hadn't seen me in a few months -- it was all euphoric. Watching the numbers on the scale tick backward, clothing sizes drop -- I'd chased that feeling for so long as a teenager, and it was finally happening. And as the compliments turned to concern I grew even more determined to hold on to that euphoria, to keep the weight off and maybe drop a few more pounds.
If someone didn't mention my weight loss, I was despondent. What was once occasional exercise became compulsive working out. Eating healthy turned into not eating. Instead of going out with friends I preferred to stay in, so I could not eat in private.
I hadn't been trying to lose weight, didn't even think I needed to. But when it happened inadvertently the euphoria was so addicting, I didn't want it to stop.
The good news is, older, wiser and having beat body issues before, I knew I didn't want to get sucked back in to a dark and compulsive life controlled completely by my weight.
I made a decision to never return to those addictions, no matter how good they felt. I stopped the feverish workouts. I returned to normal eating. I saw my friends again.
Years later, I make daily decisions to strike a balance between being healthy and being obsessive. And if the choice is between being 10 pounds overweight and 10 pounds underweight, I choose over.
It hasn't been easy. I have a job on television now and the pressure to look good and stay thin is immense. I simply don't pay attention to it.
I was recently a bride, and unlike many women preparing to walk down the aisle, I refused to embark on some crazy crash diet to look my thinnest in a corset, though the temptation was there.
And I am sure that when I have children, I'll worry about losing baby weight like every other new mother does. But I will do all I can to obsess over my baby and not those stubborn remaining pounds.
I'll bet that Rachel Frederickson can relate to much of my story. I bet that when she was at her heaviest she was unhappy, and maybe even depressed. I bet she never thought she could look the way she wanted. I bet she fantasized about what it would be like to be thin.
And now I bet she is intoxicated by the attention she's gotten for losing so much weight, intoxicated by the rush of losing another pound, by the boost in energy she has from working out. And I bet she has vowed to herself never to gain the weight back, never to return to the previous her.
I just hope that in addition to weight loss and workout techniques, the trainers and doctors on the show have equipped her to deal with the addictive behaviors that can result from successfully getting in shape. I hope they've warned her about a mental anguish that can be just as dark as the one she felt as a heavier woman, and maybe even more dangerous. And I hope they've told her that despite the thrill of losing the most weight, she will not become a "loser" if she gains some back.
I'm proud of Rachel for getting healthy. And I hope she loves who she is. But the next year will be an important and potentially dangerous one for her, with addictive behaviors lurking around every corner. I just hope she's strong enough to avoid them.
-- The opinions expressed in this commentary are solely those of S. E. Cupp.
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