From Zac Efron to Mario Lopez, see these sexy stars take their shirts off
Butler famously beefed up for his role in 2007's 300, but in August 2011, he debuted a slimmer—but still muscular!—frame in Santa Monica, Calif. in August 2011. Of his slimdown, the actor tells Us Weekly: "I'm just doing a lot of cardio and watching what I eat. I stopped lifting big weights and I'm doing yoga."
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