The 31-year-old said when she gained weight in 2002, bosses panicked and forced her to loose 15 pounds, reports mirror.co.uk.
Aguilera, who recently opened up about her new fuller physique, revealed: "During the promotion of my album 'Stripped', I got tired of being a skinny, white girl. I am Ecuadorian but people felt so safe passing me off as a skinny, blue-eyed white girl.
"The next time my label saw me, I was heavier, darker and full of piercings! Let me tell you, that wasn't an easy pill for them to swallow. I had gained about 15 pounds during promotion and during my Stripped tour. They called this serious emergency meeting about how there was a lot of backlash about my weight.
"Basically, they told me I would affect a lot of people if I gained weight - the production, musical directors. (They claimed) people I toured with would also miss out if I gained weight because I would sell no records or tickets for my shows.
"I was young, so I lost the weight quickly and was toothpick thin during Back to Basics promos and touring."
The singer also claims she put her foot down during recording for her new album "Lotus" and has refused to slim down to promote it.
She said: "I told them, 'You are working with a fat girl. Know it now and get over it.' They need a reminder sometimes that I don't belong to them. It's my body. My body can't put anyone in jeopardy of not making money anymore - my body is just not on the table that way anymore."