On the podcast, which was recorded before she gave birth, McPhee shared that her eating disorder began during her teenage years and that she began "a bad pattern of bulimia" by the time she was 16 or 17.
In her senior year of high school, she saw a therapist to help with her food issues, and enrolled in a program to further help before competing on American Idol in 2006.
McPhee's pregnancy, she said, caused her food issues to come "up in a way that hadn't been present in a long time."
"I have felt really stable in my life in the last four or five years, and my weight has been sort of more consistent," she said. "But feeling like there was a relapse after getting pregnant was really shocking and upsetting and concerning for me."
Starting from the first trimester of her pregnancy, McPhee said she was "suddenly so obsessed with food."
"I was really ravenous the first trimester," she said. "I would get so hungry... The food hunger would come on so quickly. In your brain you're like, 'Is this just the eating disorder version of me? Or is this actually my body?' It's just suddenly the cues felt really different and I didn't know how to interpret them."
"Then when I did eat, I would feel really full. It was just very confusing," she added. "... It made someone who felt like I really had it figured out... suddenly [realize] I didn't have any of it figured out."
What McPhee experienced, she said, "was definitely a feeling like I was overeating."
"Then I had that stuffed feeling, where I couldn't breathe. I couldn't figure out if I was just stuffed feeling because there was a new thing in my body that was making me feel stuffed or if I was actually eating too much food. I was eating really fast," she said. "There's just a lot of anxiety. So you're like, 'Is the anxiety around food hormonal-based or is it coming from an eating disorder?' I couldn't determine the two."
McPhee also noted that she had "such a distortion of the way that I looked" during her first trimester.
"I look back at these pictures and my husband was documenting, like, every day, because I'd be like, 'Take a picture of me now. Am I showing?' And I look back and I'm like, 'Oh my god, why was I so hard on myself?'" she said.
In order to combat her fears, McPhee reached out to a psychiatrist she had worked with previously.
"He said to me that it's really common for women who have struggled with eating disorders in the past to have almost a relapse, in some sense, when they enter pregnancy," she recalled. "It made me feel so much better that I wasn't alone in that head space. By just meeting with him and him talking me through it. It wasn't like he gave me a bottle of pills and said, 'Here's your pills for anxiety.' That's not what he did when he met with me, but he just sort of talked me through it and asked questions."
While the situation "got a lot better" in the second trimester, McPhee still counts her food issues as "the hardest part of pregnancy." Though she didn't have a "full-blown relapse," McPhee is still proud of herself for working through her food issues while pregnant.
"I weathered it and I'm really grateful I'm at the end of it, that I feel this good," McPhee, who gained 40 pounds during her pregnancy, said. "I look in the mirror and I'm like, 'Yeah, my legs, thighs, arms are a little bit thicker, but I'm OK with it.' I'm really OK with it."