"The Bible says that God wants you to be as healthy physically as you are spiritually," said Warren in a video announcing the event. "The plan will help you feel better, look better, have more energy, get in shape, and use your body the way God wants you to."
Renowned physicians Dr. Daniel Amen, bestselling author and psychiatrist, Dr. Mark Hyman, a metabolism expert, and Dr. Mehmet Oz, a cardiac surgeon and host of The Dr. Oz Show, will join Warren at the church's main campus in Lake Forest, Calif., to kick off the initiative.
Warren will speak about spiritual health while the three doctors address topics under their area of expertise.
Obesity is a growing epidemic in the U.S., said Warren, who cited statistics showing 76 percent of Americas are overweight. His church is not excluded from the figure. Last fall, he noticed that during a baptism service of more than 800 people that most of them were overweight.
The megachurch pastor promised to commit to the program, revealing that he has gained 3 pounds each year during his 30 years at Saddleback.
"I can't ask you to get healthy if I won't," he said.
Around 6,000 people signed up for the program when Warren introduced it during a sermon last year.
The church will launch a website, www.danielplan.com, to help members track their progress through an interactive profile and tips on meals, food shopping and exercising.
"Why are we doing this? Because Jesus died for your body and the Holy Spirit lives in your body. The Bible says we will one day be held accountable before God on how we were stewards of the body He gave us," said Warren.
At the Saturday event, medical professionals will record health numbers and attendants will have the chance to take a "before and after" photo.
Warren said there will also be a monthly conference call to encourage those in the plan. Small groups will also be able to follow along in a six-week curriculum.
The fitness plan is part of Saddleback's Decade of Destiny, the church's spiritual growth and expansion plan for the next 10 years. The campaign aims to equip church members in seven key areas: spiritual, physical, financial, relational, vocational, emotional and mental.
Hoping that the event will also serve as a "non-threatening" platform for outreach, Warren has asked his congregation to invite their friends and neighbors to attend.
The Daniel Plan's launch event will begin on January 15 at 8:30 a.m. local time. A live simulcast of the event will be available on the Daniel Plan website.