Jessica Chastain gets 'sick' if she doesn't stick to her Vegan diet

Jessica Chastain gets "sick" if she doesn't stick to her Vegan diet.

The 'Interstellar' star swears by abstaining from meat, fish and dairy products as it boosts her energy levels and believes she is intolerant to fish.

Asked what her biggest vice is, she told Radio Times magazine: "I don't do drugs and I'm vegan.

"I was feeling very sick and my friend said, 'Why don't you eat vegan for two weeks?' The first week I was very hungry, and the second week I felt amazing. When I finished the two weeks I went to a restaurant and ordered fish and risotto and I felt sick again.

So, I decided to just eat vegan.

"Now, I have so much energy and I do four movies a year. I also don't drink coffee usually - but when I go to Italy [her husband is Italian], I might have an espresso."

The 46-year-old actress has been an advocate of veganism for a long time, as well as having a passion for sustainability.