"I began to consider the effects of food when my father was diagnosed with throat cancer in 1998," she told the magazine. "I started to research anti-cancer diets in hopes that he would try to hit it from all angles."
Bruce Paltrow died in October 2002 at age 58 due to complications of cancer and pneumonia. But Paltrow, 40, used his health struggle as a catalyst for change -- eliminating dairy and gluten in her diet.
"It's about being mindful about what you are putting in," she explained. "Good whole foods are the way we have eaten for generations. It's amazing how good you feel when you just cut out the processed stuff."
Paltrow, married to Coldplay frontman Chris Martin for 10 years, also has their kids, Apple, 8, and Moses, 6, follow the diet.
In her 2012 cookbook, It's All Good: Delicious, Easy Recipes That Will Make You Look Good and Feel Great, she writes, "Every single nutritionist, doctor and health-conscious person I have ever come across...seems to concur that [gluten] is tough on the system and many of us are at best intolerant of it and at worst allergic to it."