Kevin Smith has become a vegan.

The 47-year-old comedian-and-director has been forced to dramatically change his lifestyle after he suffered a massive heart attack in February this year, and his 18-year-old daughter, Harley Quinn Smith, has encouraged him to take up the meat and dairy-free diet.

She told the New York Post's Page Six Column: ''He's doing really, really great. He's the healthiest he's ever been, he's vegan now, which is amazing.''

Harley - who stars in new movie 'All These Small Moments' - revealed she has been vegan for two years and has been trying to get her dad on the clean eating bandwagon for some time.

She added: ''Now its finally happened and I'm so happy.''

Harley recalled a recent trip to restaurant Veggie Grill with her father, revealing: ''He had the vegan nachos and loved them.''

Harley is Kevin's only child with actress Jennifer Schwalbach Smith to whom he has been married for 19 years.

The 'Clerks' filmmaker required emergency surgery after collapsing from a heart attack backstage at a comedy gig in California.

Doctors told him they found 100 per cent blockage of a major artery.

But Kevin insists it was the ''best'' thing that has ever happened to him, forcing him to change his lifestyle, now he's lost over 30 pounds from a largely plant-based diet.

He said: ''Honestly, the heart attack was the best thing that ever happened to me.

''This is the weight I was when I met my wife, so this is a good weight to be at. Last time I was at this weight, I scored, big time.''