How Kristin Cavallari Got Amazing Abs Seven Months After Giving Birth

— -- In May, Kristin Cavallari gave birth to her second son with husband Jay Cutler.

By the looks of it, she's already back to her pre-pregnancy shape.

"Just got a nice little workout in. Yes those are baby monitors behind me," she wrote on Instagram. "#GottaLoveNapTime"

This past July, Cavallari, 27, revealed that she'd already dropped 20 pounds, but was having trouble losing the last five. She said she's breastfeeding and "working out really hard," but she watched her diet too.

"I don't put any toxic chemicals in my body. I'm a freak about reading the ingredients. I don't count calories, I just read what's in whatever I'm going to be putting in my mouth," she told Access Hollywood. "I try to be as organic as possible I stay away from dairy for the most part... I'm actually allergic to cow's milk so that's reason enough but I also, I think that that's the number one weight gainer. If you're going to get one thing out of your diet, I think it should be dairy."