tonight on "nightline" -- he was 16 years old and over 400 pounds until a highly controversial surgery and a beautiful tv anchor. tonight, the incredible year-long transformation and what he's gained by losing big. on real estate, it's the flip side of the global meltdown. millionaires from all over the world snapping up the most expensive properties. why the global 0.1% is moving in. and "good morning america" anchor robin roberts announces after defeating breast cancer she's taking on a new health

challenge. >> i am going to beat this. >> all about robin's new battle. good evening. i'm bill weir. thanks for joining us, well, between prom and college applications, most teens have plenty to fret over without adding body image to the list. but for hundreds of thousands of high schoolers these days concern over size goes far beyond fashion or vanity. it comes down to life or death. last year, my co-worker sin tcy mcfadden interviewed a teen. one year later, this is what she found. >> give me a large fry. >> reporter: when we first met nick preto last june fast food was a way of life.

>> can we get a beefy burrito. burrito, cinnamon twist. >> reporter: driving around his neighborhood in baytown, texas. >> i see burger king, mcdonald's. >> reporter: at just 16 years old, nick weighs an astounding 403 pounds. the result of lots of meals like this. oh, double-stuff oreos sonic blast, i wonder how many calories that is. i asked him to show me what he eats on a typical day. 7,000 calories. three times the suggested daily intake for an adult male. it's both appealing and revolting isn't it? >> yeah. i mean, this alone right here -- >> reporter: yeah, those are the chicken nuggets. but as happy-go-lucky as nick is, he is not satisfied with his life. he wants to change. why?

well, one reason -- >> it's going to sound cheesy but girls. >> reporter: what about girls? >> you know, senior year, you want to date the homecoming queen. you know, you want to have the cutest girl. i guess, since i've been bigger nothing has really happened with the ladies. >> reporter: but nick's doctors tell him if he doesn't lose weight, the ladies are going to be the least of his problems. nick is careening towards an early death. he's already prediabetic and suffering from sleep apnea, liver damage and joint pain. nick believes the only help is a radical one. he decided to undergo a surgery still highly controversial for teens, gastric bypass surgery. >> okay. >> reporter: nick's surgeon dr. mary brandt was hesitant about doing such a major and irreversible operation on a teen. >> i really didn't think it was

a good idea. metabolically changing a teen made no sense. this is the first generation that's not going to outlive their parents. >> that's a shocking notion. >> reporter: have you thought how your face is going to look? >> i'm going to have a slim face. i'm going to have surgery in 3 hours and 48 minutes. it's been 48 minutes now. he's really hanging in there. >> there you go. >> reporter: the procedure takes about two hours, completely rewiring the digestive system and reducing the stomach to the size of an egg. nick is so confident that he will now be able to lose weight quickly that he makes a bold bet with me. where do you think you'll be in september. >> i'm going to push myself and say i'm going to lose 60 pounds. >> reporter: 60? in six weeks you're saying? >> yeah.

>> reporter: it's tough as nick adjusts to eating tiny portions. look at you, how good you look. seven weeks later, he's come to new york city. you look amazing. >> thank you. >> reporter: it's obvious, he has lost a lot of weight. what does this number have to be? >> at least 317. >> reporter: all right, 317 or lower or i win the bet. 315.2 that is incredible. i've never been happier to lose a bet ever. nick, his mother toni and i go out for a healthy lunch. she tells me it hasn't been easy, he's vomited a lot. he's been on an emotional roller coaster. >> i cry at sad movies and chick flicks and stuff. >> reporter: but he's determined to keep losing weight and is ready to make an even bigger bet with me. six months, you weigh 315 today. >> i'm going to go 100.

>> reporter: you're going to weigh 215 six months from now? >> yeah. >> reporter: i'm with you, pal. >> all right. >> reporter: we stayed in touch with nick for the last nine months, all through his senior year. he joined the swim team and the water polo team. and a few weeks ago, nick agreed to meet me in central park for the big weigh-in. look at you! oh! you feel smaller. >> thank you. >> reporter: you look fabulous. >> thank you. >> reporter: how are you feeling? >> i feel good. >> reporter: he brought a special show and tell that he keeps as a reminder of how far he's come. oh, my. >> yeah, these are when we first met you. >> reporter: you've got a whole other person in there. >> me and my brother actually last week, both of us fit in these jeans. >> reporter: a year ago, his waist was 60 inches. today, it's 34.

and when he stepped on the scale -- whoo-hoo, 247. he's lost another 67 pounds not quite the 100 pounds he was predicting. in honor of an extraordinary journey that you let abc be part of, we just wanted to say you're the most valuable player. >> all right. >> reporter: you put your joins in there. >> of course. >> reporter: but better than any cheesy "nightline" trophy, nick now has a girlfriend. and the two just went to the senior prom, a night never to be forgotten. >> it's a great prom day. >> reporter: a year ago, nick just wanted to be a regular kid is now unstoppable. >> cynthia, do you mind, i'm going to the prom. >> reporter: for "nightline," i'm cynthia mcfadden in

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we are all too familiar with the real estate hit the country took in the recent recession. you've probably heard about the looming disaster over in europe as well. somehow, flocks of passport toting rich guys are turning america recession proof.

here's matt gutman for the realty check. this is alejandro gozan. this is is the lamborghini. this is the condo the 28-year-old just got in cash for his mother. it's sizzling up to 300 calls a day. >> yeah, but for how long? is it for a year lease? >> reporter: he made a fortune flipping houses since college, it's business as usual. for the rest of us, home ownership is at a 15-year low. property values are expected to stagnate the rest of the year, after plummeting the past four years but in cities like new york, los angeles and miami, mini bubbles are popping up. they are places where perspective buyers grew up in

sports car or were ferried in. and metrics don't really apply. the hard-partying gazon took us inside a place mainly populated by brazilians russians, americans and european who say this is much like their crumbling local economies. in fact, the $1 million plus condos are hotter than ever. up nearly 20% over the previous high set in 2006. we road along as we went to see the three-story penthouse perched over the atlantic. $11 million. and yet this, he said, 80% of his deals are in cash. i want to see the checkbook. >> i didn't bring it. >> come on! you didn't bring it. what are you going to buy it if you need to put down money now? >> reporter: just three years ago, he said, he made a killing

in the epic bust. now folks like him are gobbling up anything they can get their hands on. >> i want to come in and be a little bit higher. >> reporter: as it turns out, this is not one of them. so you didn't love this place? >> i like it, i like the flow-through. i feel it's a bit narrow. but i like the layout. >> reporter: his guide in the gilded world most of us can never afford is agent danny hersberg. what do you think? >> it's not bad. >> reporter: three bedrooms, $19.5 million. it's not every day you see a helicopter pass by beneath you. the jade, six bedrooms, $11 million. and the penthouse at the four seasons hotel, two bedrooms and $13.5 million. so welcome to the master suite.

okay. i don't want to be a complainer but, a queen size bed, this is bigger than my apartment. the bidding wars so entertaining -- let's cut to the chase? how much will you sell this house for? >> $3 million. >> reporter: it was exported to new york, more bidding wars. and there a russian billionaire recently bought this $88 million condo and an anonymous buyer snapped up an unfinished penthouse for $90 million. now, the most expensive home in new york city, a couple years ago, these deals were unheard of. but now they say it's different, unlike the subprime real estate, a lot is bought with cash. >> all of a sudden, there's foreign investment, you have people coming in from brazil, argentina, a lot of russian

buyers, canadian buyers. >> reporter: a few days, i learned what to look for in the unique apartment, the german marble, french faucets. and alejandro, he's still locking for that big deal, that perfect place. aren't we all, i'm matt gutman in miami. just ahead, this morning, she announced it to millions of viewers. now, we'll tell you all about "good morning america's" robin roberts' new health challenge. there's another way to help erase litter box odor. purina tidy cats. only tidy cats has new odor erasers... making it easy to keep things at home... just the way you want them. new tidy cats with odor erasers.

if you are one of the millions who wake up to that mega watt smile of robin roberts, maybe you wondered what's she like really? well, we can all attest, that smile, that warmth is always on, even when she was slugging it out with breast cancer years back. she lets the camera take on the fight after the revelation this morning that the cancer treatment gave rise to a rare and serious blood disorder. once again, our hearts are with the woman who's done more than her share of grinning through the pain. it's not easy getting up in the middle of the night to do two hours of live national television each morning. >> thus begins another broadcast day. >> but you wouldn't know it watching her. >> magma! >> you're not on three-inch heels right now. >> it's incredibly hard getting breast cancer and realizing you

should shave your head before the chemotherapy makes it all fall out in clumps. but you'd never know just how hard watching her. >> i feel good, i feel strong. not going to shed a tear. >> take a deep breath, exhale. good. >> and it is physically and emotional brutal to undergo months of chemo and radiation, even when diane sawyer smuggles in some of your favorite pop eye's chicken. >> can you tell the difference between the spicy and the not spicy. >> but we just never knew how brutal, that's why there was never any doubt that robin roberts would win. she did. she beat cancer. this spring, her "gma" team beat the "today" show. and when president obama wanted to make major news, she got the

call. and all the points she scored at southeastern louisiana put her in the women's basketball hall of fame. but what we didn't know all those victories were tempered by a new disease. we didn't know until the end of this morning's "gma." >> it is something called mds. miyelodysplastic syndrome. if you're looking saying, what? i was doing the same thing. it's a rare blood disorder. dr. richard besser has been holding my hands through this. >> dr. besser's first word of advice, don't google the disease because it becomes leukemia. but he said robin has a couple things in her favor, access to superior care, strong health and a strong family. >> your approach is bone marrow

cancer. the better the recipient, the better. >> my big sister is virtually a perfect match and she is going to be my donor. >> and if there is power in crowd source love, robin has that going for her, too. the well wishes have been pouring in all day. including a tweet from the white house. we believe in you, wrote the first lady. so as it seems, robin will head back into the chemo room and will probably brighten a few moods while she's there. >> oh. >> and when the opportunity is right she will use her morning megaphone for all of us to join the bone marrow registry. with time off for the transplant, she'll continue to answer that call that starts so many days for so many people -- >> good morning, everyone. he all while battling back to