(USA Today) -- Pastor Rick Warren's life has always been an open book.
He spread the word about how to live a Christ-centered life in his best-selling book, The Purpose Driven Life.
Over the years, he and his wife, Kay, have shared heartbreaking experiences, including her battle with breast cancer and, more recently, the death of their son, Matthew. He struggled with mental illness and committed suicide by a self-inflicted gunshot wound in April. He was 27.
"2013 was the worst year of my life." Warren says. Matthew "had a tender heart and a tortured mind."
Now, in his new book, Warren, 59, founding pastor of Saddleback Church in Southern California, is trying to help people heal their health. The Daniel Plan: 40 Days to a Healthier Life (Zondervan, out Tuesday), written with doctors Mark Hyman and Daniel Amen, details a lifestyle program that helped Warren lose 65 pounds in 2011 and propelled members of his congregation to get healthier by dropping more than 250,000 pounds collectively that year.
It has five essential components: food, fitness, focus, faith and friends. "The last two components - faith and friends - are what I call the special sauce that makes the Daniel Plan unique," Warren says. Focus is also critical because "it's not just what you eat that makes you unhealthy, it's about what's eating you."
The program incorporates healthy eating, regular exercise, stress reduction, prayer and support from other church members in small home groups.
Warren was inspired to create the plan after he baptized more than 800 people one day in November 2010. After lowering more than 145,000 pounds of weight into the water, Warren says he thought, "Wow! Everybody's fat!"
He concedes that it wasn't a very spiritual thought for a pastor to have, but he also thought, "I'm fat, too. I'm as out of shape as everyone else is."
"That was the aha moment" that started the ball rolling, "but we didn't start the Daniel Plan right away." He tapped three well-known doctors who were all best-selling authors - Hyman, Amen and Mehmet Oz - to help him create the plan.
Then, in January 2011, Warren says he went in front of his congregation of 20,000 people and said, "Guys, I need to repent."
"I told them I had gained 2 to 3 pounds a year, and I've been your pastor for 30 years, so I needed to lose about 90 pounds."
He invited them to join him. "I figured maybe a couple hundred people, but that day, 12,000 people signed up." Warren's church, which has eight campuses in Southern California and several international campuses, has an average weekend attendance of 22,000.
The title of the Daniel Plan (danielplan.com) comes from the first chapter of Daniel, in which Daniel challenges the king's official guard to test some young men to eat the king's diet of rich food while Daniel and his three friends eat healthy fare including vegetables, Warren says. "We just took the title from that concept. It doesn't try to follow what Daniel ate, because the Bible doesn't tell us exactly what he ate."
The food portion of the plan involves eating "healthier, fresher and more natural foods," he says. "The line we use is: 'If it grows on a plant, it's healthy. If it's made in a plant, don't eat it.' My rule is no snacks, no sweets, no seconds."
Co-author Hyman, a family doctor who has written books including The Blood Sugar Solution and Ultrametabolism, says the message about food "is very simple: Eat whole, real, fresh foods, plant-based foods" and stop eating processed foods, junk food, fast foods, fried foods and artificial sweeteners.
At 6-foot-3, Warren weighed about 295 pounds when he began following the plan in January 2011. He lost 65 pounds by eating more nutritiously, cooking healthy recipes, drinking more water, getting more sleep and working out.
He was doing well on the program before his son died. Matthew suffered from mental illness his entire life, Warren says.
"When Kay was pregnant with Matthew, she got some kind of unusual rash or disease that left her bedridden for months. During that pregnancy, I had three fears: Is my wife going to live? Is the baby to going live? And is the baby going to be healthy? Kay lived. Matthew lived, but Matthew was not healthy. He had a tender heart and a tortured mind. Your character is not your chemistry. He had borderline personality disorder. He struggled with suicidal thoughts all of his life."
Warren says he gained "about 35 pounds back in six months of grieving my son's suicide."
The weight regain was tied to lifestyle changes. "My back went out, and I wasn't able to exercise for an extended period. I didn't feel like doing anything, and our members who are so loving were bringing us meals every night. They weren't necessarily healthy meals. They were rich in creams and enormous portions, far more than we could possibly eat. It was comfort eating. I wasn't making some good choices in terms of what I ate.
"I didn't sleep well for months, and when you don't sleep well, your hunger level goes up. I fell off the wagon. All those pounds I had lost kept finding me.
"But as anyone in recovery will tell you, setbacks are part of the process in long-term change. Rather than beat myself up, I simply asked God and my friends to help me get back on track," he says. "People often learn from their weaknesses.
"When I began to get a handle on the grief, I already knew what to do" to live a healthier life.
So far, he has lost about 25 pounds, and he intends to drop more. "I am going to prove that this plan works twice.
"I really do eat healthy," he says. He has a garden and grows 57 different kinds of vegetables from asparagus to zucchini to tomatoes. He does it "partly for stress relief," plus "there's nothing that beats the taste of something you pick right off the vine."
Warren says he's back to working out with a friend who is his trainer-accountability partner. "I have four different workouts so I don't get bored" - a hiking workout, a swimming pool workout, a treadmill routine and weight-training exercises.
Co-author Amen, a psychiatrist, member of Saddleback Church and author of numerous books including Use Your Brain to Change Your Age, says that "exercise is the fountain of youth in so many ways." You don't have to do marathons, he says. You can walk briskly for 45 minutes four times a week and lift weights two times a week.
But it's more than diet and fitness that are essential to making this program work, Warren says. He believes one of the main reasons for the Daniel Plan's success among church members is the support they received from their home groups.
Prayer is another key, Warren says. "We talked about not just eating right but thinking right. We were praying for health. I tell people if you prayed as much as you worried, you would have a lot less to worry about."
He is convinced that churches are the best place for people to come together to get healthier. There are more than 2 billion Christians around the world, so the church "is the largest distribution center on the planet," he says.
His program also includes a separate journal, out Tuesday, and a cookbook, out in April. There are additional resources, such as DVDs, for individuals and churches who want to use the plan at danielplan.com. Proceeds from the books go to Saddleback Church's charitable efforts, including one that helps care for the sick.
Some have questioned Warren's mix of church and health, but he says: "You think that God is only interested in your soul? No, he is interested in your body, mind and soul. Jesus went into each village teaching, preaching and healing. The Daniel Plan has to do with healing.
"The Bible says, 'God made my body; Jesus died for my body; the spirit lives in my body.' So I had better take care of it."