The Black Eyed Peas singer explained that she has healthy meals delivered but finds it difficult to stay disciplined.
She told Allure: "I have a meal-delivery service; Diet Designs. They're amazing - they'll have butter lettuce and avocado and pink grapefruit. They do butternut-squash enchiladas, which are really good.
"I also get these pressed juices delivered to my house, so I get all these different and wonderful vegetables. My problem is my discipline. I see a Jack in the Box or a Del Taco, and I will impulsively want it. I'm a work in progress in that area."
Fergie also admitted that she wears two sports bras in order to keep her assets under control.
"For your shoulders, if you have breasts. There's a lot of... waving," she explained.
The 'My Humps' hitmaker also insisted that she has learned to accept her "unique" nose as it makes her "interesting".
"I've learned to love my nose because it's unique. It's interesting, and it just makes me a little different," she added.
Fergie recently announced that she is not expecting husband Josh Duhamel's baby.