While Matthew's transformation may startle you, it's not the first time we've seen actors go gaunt to prepare for a role.
Gotham's masked crusader himself, Christian Bale, lost 63 lbs., which was a third of his body weight, to play an insomniac in The Machinist.
Natalie Portman dropped 20 lbs., to play a ballerina in Black Swan. Natalie mainly ate carrots and almonds and danced for five to eight hours a day. She later admitted to Entertainment Weekly, "There were nights I literally thought I was going to die."
According to Anne Hathaway, she lived off of two thin squares of dried oatmeal paste per day and lost 25 lbs. to prepare for her upcoming role in Les Miserables.
While these are extreme examples of weight swings, Matthew's body transformation and those of the actors above did inspire me to encourage my readers not to follow these silver screen examples or get caught up in so called "yo-yo dieting."
Losing and regaining weight over and over again has been linked to high blood pressure, high cholesterol, diabetes, depression, heart disease and cancer. And it can even impact your general immune system. What's more, studies show that the more one "yo-yos," the more the body's physiology can change, making it increasingly difficult to lose weight and keep it off.
How to Avoid the Yo-Yo EffectNo crash diets!
Uber-restrictive diets are miserable to go through and impossible to maintain. Instead, try eating smaller, healthier meals throughout the day. Include fiber and a high-quality low-fat protein to keep you feeling fuller longer.
No extreme workout binges!
Suddenly increasing your intensity and duration of activity can lead to injury and, just like crash diets, it's an impossible routine to maintain.
Most importantly, be patient with yourself.
Make small, realistic changes to your routine and lifestyle that you can maintain with consistency for a lifetime.
Have a fitness question? Tweet me at @harleypasternak or leave a comment below!
Check back every Wednesday for more insider tips from celebrity trainer Harley Pasternak on Hollywood's hottest bodies – and learn how to get one yourself! Plus: follow Harley on Twitter at @harleypasternak