Winter, 17, went under the knife in June (15) to reduce the size of her chest after suffering back problems and bullying over her appearance.
Hyland has now praised her co-star's decision, telling E! Online, "It's something we've been talking about for a long time... I'm super proud of her. I'm super happy for her... She's a tiny girl. We're practically the same size. I'm about a half of an inch or an inch taller than her and I can't imagine carrying that weight. She's happy and most of all, she is healthy. She's glowing. As long as she's healthy and happy, that's all that matters to me."
Winter debuted her new figure at the Teen Choice Awards in Los Angeles on Sunday (16Aug15).