"We all have to suffer through bouts of self-doubts and self-criticism," the This is Us star says

She has a hit show, a happy marriage to Taylor Goldsmith and new music, so it’s no surprise that Mandy Moore is feeling on top of the world.

“I feel so grateful for where I am in my life personally and I feel very fulfilled and very satisfied,” the This Is Us star tells PEOPLE. “[In our 20s] we all have to suffer through bouts of self-doubts and self-criticism. But none of that matters. All you’re doing is wasting time and energy when you could be pouring it into something way more productive.”

“I feel better at 35 than I did in my 20s. I have a very healthy relationship with my sense of self and with my body,” says the actress.

In addition to changing her mindset, Moore switched up her diet. “I try to make a good point of knowing what I’m putting in my body because I understand the connection with how I feel,” she says.

Mandy Moore
Mandy Moore
| Credit: Leon Bennett/WireImage

“I went to a functional medicine doctor and figured out things that are definitely not making me feel great. Random things like cow’s milk, gluten, salmon, soy and apricots. I took them out of my diet and it’s made a world of difference. I have more energy; I don’t have that fog and my digestive issues have pretty much resolved themselves.”

Moore has also partnered with the wellness company Nature’s Way, which celebrates its 50th anniversary this year.

Mandy Moor
Credit: Matt Sayles/AP

“I have been a fan of Nature’s Way for many years,” says Moore, who enjoys the brand’s supplements. “The elderberry gummies are always on me,” says Moore. “They taste amazing and they support your immune system. I also take the Alive! multivitamin. I generally feel better having them as part of my routine.”

Moore says in addition to working out, getting enough sleep and taking supplements, she recognizes the importance of mental and emotional health. “It’s about how you speak to yourself and how you speak about others,” says the actress, who also practices guided meditation. “I’m making sure I’m focused on self-care as well.”