aamir khan dangal

During the launch of his 'PK' DVD Aamir Khan also revealed that he is currently weighting 90 kgs and all the weight he gained is for his movie Dangal in which he is playing the role of wrestler.He plans to shed kilos next year in order to look like a 27-year-old man for his film. He also said that he is learning Haryanvi language and wrestling.
anydrama.com

Right now, I am learning wrestling and Haryanvi, and putting on weight. So, you can say I am in full prep mode. Currently, I am at my heaviest. I weigh 90kg, which is a lot for a person of my height. - Aamir Khan

The scenes where he plays the older version of the character will be shoot first and after loosing weight rest of the movie scenes shoot with younger look who will be seen as an ex-wrestler in the film.

Then, we will take a four-month break, during which I will follow a very strict diet, similar to what I did during Dhoom:3 (2013). I will cut down my body fat to nine per cent. I have to acquire the kind of physique I had in that film and shoot for another 15 days, I don’t think I need to put on any more weight, because I have to lose it all to play a 27-year-old man in the same film. So, the heavier I get, the tougher it will be for me to cut down later on. - Aamir Khan

The film is expected to be released in December 2016.