How do Actors gain and lose weight so easily? Is this physically dangerous?

Prosthetics and padding, maybe?

no it isn't healthy at all.

Matt Damon lost a ton of weight for one of his first film's Courage Under Fire. (he went from normal size to really skinny for the heroin addicted scenes.) He had to be on some sort of heart medication for a year afterwards.

Renee Zellweger was given a special dietitian who supervised her weight gain for Bridget Jone's Diary. (she drank a lot of plant based shakes)

I read he actually gained the weight.

I'd like to see a doc where we see them in training 24/7.

None of the wild swings in weight or the massive gains (and then loss) of muscle is healthy. The only parallel I can think of are high school and college wrestlers. So many of them yo-yo on weight gain and loss during their competitive years on the mat that afterwards their bodies have settled on a certain metabolism, the guys still eat as if they're wrestling, they no longer exercise as they did in school and man do those guys get fat fast. It's amazing.

Chris Evans, who plays Capt America or Chris Pratt from Guardians of the Galaxy put on so much weight between making Marvel movies. Their bodies crave calories, they are not working out for a movie and boom! they become very doughy quickly.

I wonder if it's possible to re-train the body after it's been punished to look a certain way for a role?

It's easier than it looks, OP.

Unrelated but why did Bale have a cockney accent or whatever it was at the Golden Globes? Is that a working-class affectation?

Laxatives

After a certain amount of yo-yo-ing the metabolism is fucked. Which is why so many people who have been fat for many years and tried multiple diets just stay fat Vene if they eat normally.

Fuckin terrifying!

Renee Zellweger looks bulimic, r2. She has the classic chipmunk cheeks.

Matthew McConaughey destroyed his long standing good looks, playing an AIDS patient. He hasn't got them back, and they aren't coming back. He might have stayed hot enough another 10 years but nope, done.

It has to do with he fat loss in the face.

R7, Bale is Welsh. That is his natural accent.

I lost weight quickly from a serious infection and couldn’t hold food down, and never gained it back in my face, totally agree. I dropped two shoe sizes and was able to double-cross my legs they were so skinny! Was scary.

Because gaining and losing weight is easy, particularly for men. Once you get over the hurdles of emotional eating and eating as entertainment/something-to-do, a person can gain and lose weight as needed with relatively little fuss. As others have said, going up and down drastically wrecks your metabolism and is hard on the body. Someone just posted a recent picture of Chris Pratt. He appeared to have gained 40 pounds of fat in the span of a few months. That's not healthy. Where things get tricky is where men develop significant muscle mass over the course of a few months. That's likely steroids. But weight fluctuation is easy to manipulate.

Cocaine

R13 I was just about to ask if Bale's accent at the GG sounded that rough and working class. It was definitely not cockney since he did pronounce his H's correctly and I somehow remember cockney from hearing Kate Moss speak. It didn't sound grating to me, he isn't Mary Poppins nor the Queen but it was okay.

Did McConaughey actually ruin his looks by losing weight? Is that possible?

R5 Chris Evans and Pratt aren't comparable. Pratt gets fat. Chris Evans doesn't gain weight, he loses muscle but he's still thin. His face sometimes fills out but that's usually when he's been partying too much and has more to do with what he's eating(or drinking) and not really related to his overall bodyweight. I don't think I've ever seen a picture of Evans where he's been anything that could be called overweight.

It was one thing for Bale to do this in his 20s and 30s but he's in his mid-40s now.