Actress Chrissy Metz details the abuse and 'weigh-ins' she suffered in her childhood.

In an emotional new book, This is Us actress Chrissy Metz, 37, opens up about a childhood marked with – not defined by – abuse and humiliation around her weight.

Her father, she writes in her memoir This is Me released this month, left her and her two older siblings with their mother, Denise, when she was eight.

Her mother remarried a man Metz calls ‘Trigger’. And, though he was loving and affectionate with his biological children, he treated her – especially her because of her weight – with bouts of hot affection and cold disdain.

“My body seemed to offend him, but he couldn’t help but stare, especially when I was eating,” she writes, People reports.

“He joked about putting a lock on the refrigerator. We had lived [in poverty], with a lack of food, for so long, that when it was there, I felt like I had to eat it before it disappeared.”

She said she – like many others who’ve experienced something similar – began binge eating in secret. She would wake in the middle of the night and cram her body with the food that would bring her immediate satisfaction. Anything that wouldn’t leave a trace, but that would effectively fill her hunger.

“Food was my only happiness,” Metz writes.

Soon, she said the physical abuse started.

"I don’t remember why Trigger hit me the first time. He never punched my face. Just my body, the thing that offended him so much. He shoved me, slapped me, punched my arm. He would hit me if he thought I looked at him wrong," Metz recalls.

She said the physical abuse was one thing, but the humiliating ritual that began when she was 14 - when Trigger started bringing out the scales and forcibly measuring her body weight in the kitchen - was another type of torment entirely.

"He’d get the scale from the bathroom and clang it hard on the kitchen floor. 'Well, get on the damn thing!' Trigger would yell. 'This is what you need to know'."

"He sat in a chair next to the scale as I got on. 'Good God almighty!' he yelled every single time. 'Why are you getting fatter?'"

Do you need to love your body? Post continues below.

Her childhood wasn't all darkness and hostility, however. With Metz saying she enjoyed moments of quiet intimacy with her stepfather, when they'd watch television together, for example.

She couldn't understand him, but she loved him. She still does, now.

"I really did love him. This man did more for me than my father ever did," she writes, People reports.

"He was smart, and I was allowed to quietly join him in watching the Ken Burns Civil War documentaries on television. I clung to [these points of connection] because I needed to figure out why this person could do right by me as a provider, but be unable to love me."

And with that, Metz - who is today happy with her body and her success - has summarised the complicated relationships that grow out of abuse.

Relationships with family, and relationships with oneself.