Megachurch pastor Rick Warren's weight loss book The Daniel Plan: 40 days to a healthier life, co-written with doctors Daniel Amen and Mark Hyman, was named the Christian Book of the Year at an award ceremony in Nashville, Tennessee last night.

The award was announced at the Evangelical Christian Publishers Association's (ECPA) annual banquet. The Christian Book Awards are among the most prestigious and long-standing in religious publishing.

Warren, author of The Purpose Driven Life who leads Saddleback Church in Lake Forest, California, started the plan in 2011 when he noticed that many in his congregation were overweight. Around 15,000 church members took up the challenge and together they lost a total of 250,000 pounds in weight in the first year.

The Daniel Plan book was published in 2013 became a New York Times #1 bestseller and since then many more have joined the biblically-based drive to eat better and get in shape. There is now a workout CD and DVD, an accompanying journal and fitness gear and The Daniel Plan Cookbook.

The healthy living plan takes its name from the biblical story of Daniel who refused the rich food of the Babylonian king, Nebuchadnezzar, in order to honour God.

"What makes it different from other wellness programs is that The Daniel Plan was built with 'love' as the motivation," the website says. "It's a reflection of God's love for us. It's a story of abundance, not deprivation. A step by step approach that helps you make small changes that lead to big results. Your journey is one of progress, never perfection."

The plan places an emphasis on working together as a community to achieve your goals, and the website claims that those who do it in a group lose 50 per cent more weight than those who do it alone.

Among the evening's other winners was Nabeel Quereshi's Seeking Allah, Finding Jesus: A devout Muslim encounters Christianity, which was lauded as best non-fiction book and best new author – the first double-category win in the history of the awards. Randy Singer's The Advocate won best fiction book and Kara Tippett's The Hardest Peace: Expecting Grace in the Midst of Life's Hard won in the 'inspiration' category. Tippetts died from cancer in March, she was told that she had won the award just a few days before she died.

The Christian Books Awards were established in 1978. In order to be considered a book must "include explicit Christian content, an overtly Christian message, and/or a distinctively Christian world view." The Christian content must be "evangelical in nature" and not be against the ECPA's statement of faith. The Evangelical Christian Publishers Association is an international non-profit trade organization with almost 200 member companies worldwide.