One of those participants will win a $1 million prize in May.
Since September, Oz has urged his viewers to take on the "transformation nation" health challenge, done together with Weight Watchers.
The number of registrants has increased at a steady clip. Oz said he never imagined such an overwhelming turnout.
"It is one of the most rewarding experiences of my life," Oz said.
The program's steps include telling a friend to get moral support, registering with Weight Watchers, getting connected with a doctor, learning your family's health history, getting more sleep, managing stress better and starting new fitness habits.
A sample of 96,000 registrants who had weighed in at Weight Watchers determined they had collectively lost 672,000 pounds, or an average of 7 pounds per person, the show said.
Show officials will choose 10 finalists who they believe best embody the effort, not necessarily those who lose the most weight. Viewers will choose a favorite this spring for the $1 million prize. You need to register by Feb. 26 to be eligible.
Participants are sent emails every week to remind them of things they need to do to reach their goals. The messages are tailored to their individual circumstances.
"Fundamentally, it's about making it easier to do the right thing," Oz said.
Oz also said he hoped the project would be a model for using TV to accomplish worthwhile goals.
The Associated Press contributed to this report.