'Dangal' director Nitesh Tiwari says superstar Aamir Khan gave his opinion on certain aspects of the movie, but never insisted his suggestions must be followed.

"Aamir is a very sorted actor and he knows where he should draw the line. He is a superstar. Whenever he feels he should give an opinion, he will give that opinion, but will never insist you. He gives a lot of respect to his writers and directors. I must say many a times his suggestions has really helped the film," Tiwari said here.

In 'Dangal', Aamir will be seen playing two versions of Mahavir Phogat - as a young wrestler and a middle-aged father. Aamir put on weight to play the older version of Phogat. He then lost the excess weight for his scenes as the younger version.

Tiware said Aamir was his first choice for 'Dangal'. "I was very clear that I wanted to make this film with Aamir Khan and I am glad the producers were also happy with my choice. They then tried to fix an interview with him," he said.

'Dangal' will release on December 23.