Lena Dunham says Joaquin Phoenix convinced her to go vegan.

The 'Joker' star is known for his animal activism and passion for veganism, and during his speech at the Academy Awards - where he picked up the gong for Actor in a Leading Role for playing the titular Batman villain in 'Joker' - on Sunday (09.02.20), he spoke out about the importance of caring for the environment and eating sustainably.

He said in part of his speech: ''We feel entitled to artificially inseminate a cow and when she gives birth, we steal her baby. Even though her cries of anguish are unmistakable. And then we take her milk that's intended for her calf and we put it in our coffee and our cereal. And I think we fear the idea of personal change because we think that we have to sacrifice something to give something up but human beings, at our best, are so inventive and creative and ingenious, and I think that when we use love and compassion as our guiding principles, we can create, develop, and implement systems of change that are beneficial to all sentient beings and to the environment.''

And now, actress Lena Dunham, 33, has taken to Twitter to say the passionate speech has made her reconsider her diet.

She wrote: ''Welp, it finally happened- I do believe Joaquin Phoenix made me vegan. (sic)''

The 'Girls' creator isn't the only one Joaquin has convinced to go vegan either, as it was recently reported he's even had an impact on his Hollywood agency WME, after they gave up meat for their star-studded pre-Oscars party over the weekend.

Joaquin, 45, attended the glitzy bash alongside his mother Arlyn Phoenix and fiance Rooney Mara, and the acclaimed actor was seen tucking in to vegan meatballs.

In January, the Golden Globes served a plant-based menu, and Joaquin voiced his support for the Hollywood Foreign Press Association for its ''very bold move''.

He added: ''It really sends a powerful message.''