Have you ever wondered how McConaughey lost so much weight for his Oscar winning role in Dallas Buyers Club? Or what about Christian Bale in The Machinist? Here's how they did it.

Now, even with all the tricks in the world, it still takes a huge amount of self discipline to pull off any amount of weight loss, much less something like this.

Also, these may not be the healthiest ways to lose weight, so be cautious.

Here is what McConaughey and Bale both did to lose so much weight so fast, and of course other stars who have lost or even maintained their giant stature: