"I am who I am and I just don't have a bikini body. I don't even have a one piece body anymore! But I am loving the long rash guard, board-shorts look," the 40-year-old says.
"I've beaten myself up about not being a certain thing," she continues. "If someone says, 'Let's go to the beach today,' my first thought is, 'F––, what am I going to wear?' I remember when Amy Schumer was on Ellen, she called her midsection a 'lava lamp.' I thought, 'That was perfect! That's what I've been trying to say.' But then I saw her in Trainwreck, and she looked so good in a tiny bra and short skirt. I was like, 'No, you don't have a lava lamp.'"
Barrymore insists that she has way more important things to deal with now, like her two children, Olive, 3, and Frankie, 1, with her husband, actor Will Kopelman.
"I'm not going to pretend to my daughters that I'm pure as the driven snow… The best I can do is open up my heart to them," she says. "That's soul-baring enough. Making bad decisions doesn't make you a bad person. It is how you learn to make better choices."
Speaking of kids, the mom of two has come a long way since her days as a childhood actress. Watch the throwback video below to see footage of an adorable 8-year-old Barrymore chatting with ET at her first Oscar's red carpet.