Losing or gaining weight for a role can take its toll on the body, but many actors are willing to put themselves through it and sometimes even get rewarded with Academy Awards for all their effort.

Find out how celebrities gain weight fast, from stopping working out to melting ice cream in the microwave and drinking it. Some even manage to go up to 5,000 calories per day in order to gain all the weight for a role, and then have a hard time getting rid of it.

Renée Zellweger

With a 4,000 calories per day diet, the actress gained weight for both the original “Bridget Jones’s Diary” in 2001 and for the 2004 sequel. It was all fatty foods and ice cream the first time around, but Zellweger worried about packing on 30 pounds again. 

Renee Zellweger Weight Gain

“I had a panic attack with all the specialists talking about how bad this is for you long-term, putting on that much weight in short periods of time,” she explained.

Jared Leto

Jared Leto Weight Gain

The svelte actor packed on 67 pounds to play Mark David Chapman, John Lennon’s killer, in “Chapter 27”. If you’re wondering how celebrities gain weight fast, his way is probably the most disgusting. After melting Häagen-Dazs chocolate ice cream, Leto mixed it with soy sauce and olive oil before chugging it down. He explained he “force-fed” himself to bulk up, and even got gout in the process.

Michelle Williams

Michelle Williams Weight Gain

No stranger to gaining a few pounds for a role, Michelle Williams had to gain weight to portray Marilyn Monroe in “My Week with Marilyn”, but also for “Blue Valentine”, where she had to film sex scenes with Ryan Gosling after gaining weight. “I wasn’t watching what I ate,” she told People, but director Derek Cianfrance was less skimpy with the details: “Michelle was eating a pint of ice cream for breakfast and dinner and avocado sandwiches all day.”

See also: Celebs Who Don't Eat Sugar and It Shows

Hillary Swank

Hilary Swank Weight Gain

Another Academy Award winner, Hillary Swank put on 19 pounds of muscle for “Million Dollar Baby”. Her secret when it comes to how celebrities gain weight fast was force-feeding herself protein so she could withstand the rigorous workouts. “I would drink my egg whites because I could never eat 8 to 12 egg whites in a sitting. It’s just the worst thing ever,” she told MovieWeb.

Eric Bana

Eric Bana Weight Gain

Gaining 28 pounds for his role in “Chopper”, Eric Bana had to lose the toned look. The actor started with a lot of “beer, saturated fats, and donuts” and stopped working out altogether. He managed to drop the extra weight in 7 months after shooting wrapped.

Gwyneth Paltrow

Gwyneth Paltrow Weight Gain

“I’ve never eaten so much fried food and white flour in my life, ever,” Paltrow told Harper’s Bazaar, giving another piece of the puzzle of how celebrities gain weight fast. She had to gain 20 pounds for her role in “Country Strong”. Besides eating fried chicken and beer, not working out was also very difficult for the actress.

Rob McElhenney

Rob Mc Elhenney Weight Gain

“It’s Always Sunny in Philadelphia” star Rob McElhenney packed on 52 pounds for the sitcom’s 7th season. He needed to eat 5,000 calories per day, and he started with chicken, vegetables and rice, but quickly turned to Big Macs, getting the same calories in a lot less volume.

More: Shocking Celebrity Weight Gains

Charlize Theron

Charlize Theron Weight Gain

Theron has a different answer to the question of how celebrities gain weight fast. For “Monster”, the Academy Award winner got into the mind of her character, who hated her body. “I first began stuffing myself with Krispy Kreme doughnuts, but after a while I got sick of them,” she said, explaining that she only made her 30 pounds goal with the help of potato chips.

Tom Hardy

Tom Hardy Weight Gain

“Chicken and broccoli” is Tom Hardy’s secret when it comes to gaining weight with a lot of muscle. The actor got up to 200 pounds while filming “The Dark Night Returns”, but he also used the same recipe to bulk up for his movies “Warrior” and “Bronson”.

Ryan Gosling

Ryan Gosling Weight Gain

Probably the only actor who gained 60 pounds for a part he eventually lost, Ryan Gosling decided he wanted to be 210 pounds for his role in “The Lovely Bones”. Peter Jackson disagreed, and the ended up leaving the production. Gosling didn’t innovate, he just went for the simplest answer to how celebrities gain weight fast: “I was melting Häagen-Dazs and drinking it when I was thirsty.”