Actress Jennifer Aniston, who prefers healthy food, once ate a McDonald's burger and says her body did not react well to that.

Aniston said that once she and her fiancé Justin Theroux had to eat at the fast food restaurant as there was no other option. She revealed how her stomach got upset after eating a burger from there, reported a website.

"I'll never forget when Justin and I were on a road trip and we were so hungry. The only thing around was McDonald's. I think I ordered a Big Mac. Wow, my body did not react well to that! It was like putting gasoline in a purified system,” a magazine quoted the 44-year-old as saying.

"I am always trying to eat organic and natural foods, so that just made my stomach turn and made me feel terrible,” Aniston added.