The "Charlie's Angels" star said she gained about 40 pounds during her pregnancy as she was constantly craving cheeseburgers and ice cream, reported Contactmusic.
"My new motto is: Impossible expectations are impossible. Look, with my luck, I will starve myself, work out and then the next day get hit by a bus. And think, 'Why did I waste my time doing that?' I'm the last person anyone should look at for workout tips.
I don't have them. I don't care," she said.
But Barrymore, 37, said keeping the tot entertained is helping her stay active.
"Her first smiles (of the day) are just the greatest. I'll jump up and down and dance and sing as much as it takes to get those smiles."