Hugh Jackman believes in completely immersing himself into the character he is playing. And so for his twin releases of the tragic hero of both "Les Miserables" and "The Wolverine" - he had to first lose 15lbs and then gain about 30lbs. And while he obviously worked out like mad to get his ripped muscles, he did follow what is called 'The Fasting Diet' to achieve this.

Basically, fasting forces the body to dip into reserve fat to power itself, so many people do lose weight. The irony is fasting causes a counter-reaction and lowers the body metabolism. During fasting, the body lowers its metabolism. This in turn means that when you resume eating, the body will try and store back the fat, as fast as possible. Rigorous exercise counter this and ensures what you gain back is muscle, not fat!

Jackman coupled the fasting diet with the Paleo Diet - intermittent fasting paired with days he could eat whatever he liked - based on the Paleo diet aka what our ancestors ate - fresh meat, vegetables, fruits, nuts and seeds with healthy oils. No processed food, cereals, legumes, refined sugar or diary.

For die-hard fasting diet fans like Dr. Michael Mosley and Mimi Spencer who co-wrote the bestseller "The Fast Diet", no other diet works. According to them and their subsequent research, the fasting diet is a natural way for humans live for it mimics the environment of our ancestors. Centuries ago, food supplies were few and far so fasting was commonplace. The book advises how you can eat whatever you want (albeit in moderation) for five days a week, then dramatically cut down for two days (500 calories per day for women and 600 for men) - this is repeated every week and is referred to as the 5:2 diet. While human study on fasting hasn't come to any conclusions, in animal studies fasting did show posting results including a lower risk of diabetes and cardiovascular benefit such as lower cholesterol and blood pressure.

So is this just another diet trend or is the fasting diet a really insightful step into human health? The research is still on!

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