The 49-year-old singer-songwriter, who has recently recovered from cancer, said on US cookery programme, the Rachael Ray Show: “My sister Kathy thought the book should be called, If It Makes You Healthy, Then Why the Hell Are You So Fat?”
'But we didn't call it that,' she added, laughing.
The Grammy Award-winning artist, who is due to start a new tour in May, told the studio audience that her new cookbook focuses on her favourite recipes to boost immunity.
She said: “After my cancer, I became a student of food.”