The singer-and-actress says having 21-month-old twins Max and Emme – her children with husband Marc Anthony – have made her look at her life and make positive changes to herself.
She said: "To a certain extent, having children did change me, but it made me want to look at the places that I wasn't great and learn to love myself and take care of myself more."
However, the star insists she wouldn't be the person she is without Marc and admits he boosted her confidence enough to wear a daring gold dress at the Golden Globe awards earlier this year.
Jennifer wore a revealing gown on the red carpet, which she had not trod for some time.
She said: "I hadn't worn a dress like that since I'd had the babies. I still wasn't back to my normal self,
"But I knew Marc would be the most honest with me and he said, 'You want to wear that, you should — you look beautiful.'"
The 40-year-old star also said that she is no longer so desperate to keep a trim figure.
She added to Allure magazine: "I'm not the monster I used to be in the exercise department. You get past your 20s, you've got kids, you're kind of unmotivated.
"You want to be healthy and look good, but you want to do the least amount to maintain that."