"I'm not going to lie: There are times I play mind tricks on myself, like that the french fries are poison," the 35-year-old songstress tells the magazine.
"With desserts, I'll let myself have just one bite, but I'll look like a freak when I'm eating it, like when I did Duncan Hines commercials as a kid, just savoring every morsel."
Clearly this discipline -- however bizarre -- has paid off.
The brunette beauty graces Elle's cover in an artfully twisted mint-hued Burberry dress with a skinny belt around her tiny waist.
Inside, she shows off her curves in a body-hugging corset dress, and in another picture, a cinched Dior look comprised of a bleached python jacket and ruffled skirt, an overflowing vintage '50s bra, and peep-toe Christian Louboutin pumps.
And while she's clearly sitting pretty in this springtime Elle spread thanks to a team of stylists, makeup artists, and hair gurus (plus, of course, her own natural beauty), Fergie says she's learned to brush off any criticism derived from images that show her looking less than perfect.
"It has hurt me in the past when people say things like how 'fugly' I am or how horrible I look. I've had to learn not to give it such a high priority in life," she says.
Daily facials or not, her studly husband Josh Duhamel doesn't seem to mind, and the Black Eyed Peas singer says their marriage is stronger than ever.
"You grow a deeper love for each other, besides the initial lust and falling in love and all of that," says Fergie.
"You come to know each other a lot better, you grow together, and it makes you love each other that much deeper."
To see additional pics from Fergie's photo shoot and read more of her cover story, head over to Elle.com and pick up the May issue, on newsstands April 14.
In the meantime, read up on which other multitalented singer-actress is also gracing the cover of one of the May glossies.