So when he calls someone 'a one stop shop for health and wellbeing', most aspiring dieters might want to stop and take note.
The Wolverine star enlisted the help of health expert and nutritionist Dr Libby Weaver and it seems he has never looked back.
So what do they know that we don't when it comes to the quest for the perfect body?
Speaking to Healthista, Dr Weaver reveals the underlying factors that can thwart dieters' best-laid plans.
At the time Dr Weaver studied dietetics at the University of Sydney in the late 90s, the prevailing wisdom was that weight gain was simply caused by eating too much.