The 40-year-old 'Iron Man 3' actress said that seeing her own father's health dwindle made her open her eyes, reported Us magazine.
"I began to consider the effects of food when my father was diagnosed with throat cancer in 1998. I started to research anti-cancer diets in hopes that he would try to hit it from all angles," she said.
Bruce died in October 2002 at age 58 due to complications of cancer and pneumonia. But Gwyneth used his health struggle as a catalyst for change- eliminating dairy and gluten in her diet.
Gwyneth, married to Coldplay frontman Chris Martin for 10 years, also has their kids, Apple, 8, and Moses, 6, follow the diet.