Hilary Swank was diagnosed with mercury poisoning after gorging on fish to bulk up for her boxer role in Million Dollar Baby and spent "years" struggling to regain her health.
So now I eat pork and beef
The double-Oscar winner, 36, was a strict vegetarian throughout her 20s, but needed a protein-packed diet to build up her strength during filming of the 2004 movie, which saw her play a female fighter.
Swank started devouring huge quantities of fish, leaving her with dangerously high levels of mercury in her blood, and after struggling to get her body back to normal, she was forced to turn her back on her meat-free diet.
She tells Britain's You magazine, "I put on 19 pounds of muscle I was 29, I was a vegetarian and suddenly I was eating so much fish that I got elevated mercury problems.
It plagued me for a couple of years after that movie. "When I discovered that my health was suffering, I had to change my diet.
"So now I eat pork and beef".