Celebrities are ever-present in the pages of glossy magazines and on the big and small screens. Their private lives often draw a large massive attention from the general public, but rarely more so than when there’s a fitness transformation taking place.
Here’s a look at some well-known celebrity weight loss tales.
Christian Bale is notorious for alternatively losing huge amounts of weight and packing on slabs of muscle at the drop of a hat. His greatest weight loss episode came while preparing for his 2004 film, The Machinist. For this role, he shed 65lb of weight and put his health on the line in a major way. Reportedly, his secret was an extreme crash diet involving as little as one can of tuna and one apple a day.
While actress Mila Kunis has never been overweight, she nonetheless shed 20lb over the course of 5 months for her role in the award-winning 2010 film Black Swan. Apparently she opted for a relatively healthy diet strategy, eating at a moderate calorie deficit and having her meals prepared by a food delivery service.
Renee Zellweger is another celebrity who is famous for gaining and losing weight at the drop of a hat, most famously putting on 30lb for her role as Bridget Jones and shedding the weight again within a couple of months. To lose the weight, Renee apparently followed a high-protein low-carb diet, worked out for 2 hours each day, and regularly went on 12-mile long hikes. 
Charlize Theron notoriously gained 30lb of weight to star in the 2003 film Monster, only to lose all the weight again within a month in preparation for her next film, Head in the Clouds. The specifics of her diet during the weight loss is a bit of a mystery, but she reportedly cut down to eating two small meals a day and removing alcohol from her diet altogether. She’s also known to be fairly sporty too, with a particular interest in yoga.