Merrick Watts has revealed a striking new look on his Instagram.

The larrikin comedian, 50, who found fame as one half of Merrick and Rosso on Triple J in the late '90s, showed off his dramatic weight loss on Monday.

In footage shared to the social media platform, Watts looked every inch the buff hunk in a black workout singlet, with his hair was also noticeably longer. 

Striding across the beach looking lean and showing off muscular shoulders, he gave his followers advice for dealing with 'haters.' 

'Ask yourself two simple questions: are they the best at what they do and are they the best at what you do? The answer is always no, so you do you, because you're good enough,' the radio host said.

Watts earlier admitted that his transformation came after appearing on the 2020 season of SAS Australia.

He claimed the show helped him achieve 'the best physical and mental state I've been in in my entire life'.

Speaking candidly at the time, he said he struggled with anxiety and depression before making the appearance on the grueling Channel Seven series. 

The father-of-two said he had been in the 'worst mental state' of his life, and not even a psychologist or 10-week meditation course could help.  

'I felt like I was chipping away,' Watts said during an interview with Nova's Fitzy and Wippa.

'I did all the right things, I spoke to a psychologist, I spoke to my doctor, I did a 10-week meditation course. Nothing was working. I know that what I needed was to rebuild my confidence.'

Watts said he knew that going on SAS Australia would help him 'rebuild his confidence.'

'When I'm confident I'm very, very capable. When I'm not confident I go back into my shell... I knew that just the process of getting ready for SAS Australia would be enough to rebuild my confidence and I was right,' he explained.

'I look at myself, a year ago and when I signed up for this show I was in the worst mental state I've ever been in. I look at myself a year later and I'm in the best physical and mental state I've been in in my entire life.'

He finished: 'It's been extraordinarily good for my mind and my body.'