Clare Southern, 19, won the £97,000 (€140,000) first prize late on Saturday after being the last contestant to fall into a deep sleep.
In a final sleep-off challenge, the three remaining contestants climbed into beds in darkened rooms - knowing that the last one to nod off would be declared the winner.
Southern lasted 90 minutes longer than her rivals and survived some 178 hours on little sleep.
Although billed as the ultimate exercise in sleep deprivation, competitors were allowed occasional catnaps agreed by the producers.
"I didn't think I would last a second as soon as I hit the bed, but for some reason I just seemed to wake up and towards the very end I was dying for the toilet, which wasn't good," Southern said on being declared the winner.
"It is humiliation TV and very concerning that what we are doing is putting people's health at risk and causing them psychological harm."
Gary Wood, social psychologist
University of Birmingham
The show, entitled "Shattered" and made by the producers of international TV reality show "Big Brother", quickly attracted controversy after doctors accused it of endangering the contestants' health.
Gary Wood, a social psychologist at the University of Birmingham, had said: "It is humiliation TV and very concerning that what we are doing is putting people's health at risk and causing them psychological harm."
Several members of the group complained of hallucinations, exhaustion and paranoia during the week and on Saturday media watchdog Ofcom confirmed it was investigating the show after receiving a number of complaints from viewers.
The series started a week ago with 10 contestants competing to stay awake in a "laboratory" in east London, with the worst performing competitor voted off each night.
The group lost £1,000 from the £100,000 jackpot whenever anyone fell asleep for more than 10 seconds outside of the designated catnaps.
Contestants were put through a series of endurance tests, including watching paint dry for one hour.