Meghan Trainor Talks Mom Guilt, Oversharing and Family Drama Behind New Single 'Bad for Me'

Meghan Trainor is in her feelings.

The pop star has kicked off a new era, releasing the Teddy Swims-assisted "Bad for Me," her falling-out-inspired first single off her upcoming fourth studio album, Takin' It Back (out Oct. 21).

"It's me taking back my power and my confidence," Trainor, 28, says of the LP, the first she's created since welcoming son Riley, 16 months, with her husband, Spy Kids star Daryl Sabara, 30.

Ahead of the release of "Bad for Me," PEOPLE caught up with Trainor over a Zoom interview from her home, during which she opened up about mom life, the heartache she poured into the new track — and how she's returning to her "All About That Bass" roots.

You're doing sad-girl pop on "Bad for Me." Where did that song come from?

It's my Adele moment [laughs]. I wrote it about real events that happened to me. I really had a moment with my therapist where I wrote a letter to a family member and I sent it to them, and I thought that was perfect, but I got no response still, so it was heartbreaking. And then I wrote the song, the chorus, immediately. I did not think it'd be the first single ever. But it felt too powerful and big to not try to go first with it, to also reintroduce people to Meghan, the mother—we have emotions and they're relatable.

Lauren Dunn Meghan Trainor

It sounds like writing this song was therapeutic, too — on top of the actual therapy.

I know, right? It's terrifying also to talk about publicly because I never wanted to, and I don't want to hurt their feelings. It's already blowing up on TikTok, which is great, but also scary.

Does that happen a lot? Feeling like, "Oh, did I get too personal?"

It is so weird for me because I'm an open book and I tell everyone everything. But this one is personal because there's someone else involved. And usually I tell every detail, and this one, I want to keep that private for their sake. I don't want my fans going and finding them. So it's weird to walk on eggshells. Immediately when people even heard snippets of it, they all go, "Oh, it's about your brother, Ryan." Because everyone knows that we went through a rocky part in our relationship, but no, it's not about him.

You're returning to your doo-wop roots with your next album, Takin' It Back. Why go back to the "All About That Bass" vibe now?

I'm the biggest fan of TikTok and when [my 2015 single] "Title" blew up, it was the same time as me starting to write this album. And I was like, "The universe has spoken. They want the doo-wop. They want it back." And that song is seven years old and it's popped off! I was in a session with [songwriter] Mozella for this album, and she said, "You know what's crazy? All these artists are coming in saying, 'I want to do the Meghan Trainor sound.'" And I was like, "You mean doo-wop? What are you talking about? My first album? Okay. Easy. I'm going to do Title 2.0."

I studied Amy Winehouse's "Rehab" every day. And I studied "All About That Bass," and I was like, "Why did this work?" And I tried to just do the best songwriting I could, have purpose, have meaning in my lyrics and also talk about s--- I need to talk about like, loving of my body all over again, especially after a C-section.

RELATED: Meghan Trainor Opens Up About Panic Disorder Battle, Reveals She Had First Panic Attack on Live TV

Lauren Dunn Meghan Trainor, Takin' It Back

You wrote "All About That Bass" almost a decade ago. What was it like studying your own songwriting?

It's bizarre. I was a total different person obviously back then, and I didn't even have a life yet. Now it's almost 10 years later, and I've been through so much and had a baby and life is extra precious now, I want to live forever. I love who I am now, and I love where my family's at now. So there's more depths to my lyrics and I've gotten better at singing too. I was trying to write timeless records.

How is songwriting and your creative process different now that you're a mom?

The schedule's different because I told everyone, "Get at my house at 11 a.m. and get out by 6 p.m." So we would write a song and then I'd be like, "It's dinner time, goodbye." And we would have baby breaks. I could be like, "Be right back, guys. I'm going to go give my kid a bath." I'm lucky to have my studio right here in my house. A lot of people are like, "I don't like work at home." I love it; I don't want to go anywhere!

The luxury of that was significant, and I'm lucky enough that I can work from home and see my baby. It made me really just respect mamas who work even more. I'm lucky that I get to see him. And I talked to my therapist about it. I was like, "What is this guilt I have of not being with my kid and anger that I don't get to see him?" And she's like, "Oh, that's what every mom goes through. It's called being a working mom." And I was like, "This is bull----." But it's part of the gig.

Nolwen Cifuentes Meghan Trainor with husband Daryl Sabara and son Riley

Mom guilt is real.

Oh, you can hear that half this album is me talking about being a mom, but I turned it into a relatable way so that young teens could also vibe with us. But yeah, you can hear a lot of, "I'm doing my best."

So how is Riley doing these days?

He's a person. He's got a personality nowadays. And we found out yesterday that he needs glasses and he's going to be so freaking cute! They're going to like be strapped around his little head. I don't know how he's going to keep him on. I doubt it. My kid takes pots and pans and just slams them and doesn't flinch. He's just like, no ways and destruction. So I don't see it happening, but we'll see.