NEW YORK (REUTERS) - Lady Gaga has hit back at cyber bullies who made fun of her body during her spectacular halftime show at Sunday's Super Bowl.

"I heard my body is a topic of conversation so I wanted to say, I'm proud of my body and you should be proud of yours too," the Born This Way singer wrote on her Instagram page on Tuesday.

"No matter who you are or what you do. I could give you a million reasons why you don't need to cater to anyone or anything to succeed. Be you and be relentlessly you," she added.

Gaga, whose Super Bowl outfits included a crop top and glittering shorts, was mocked by some viewers on social media for the appearance of her stomach.

"Tried to enjoy @ladygaga's performance, was distracted by the flab on her stomach swinging around," tweeted one viewer, Nathan @negans-swing.

Others came to her defence.

"Guys making fun of Lady Gaga's 'muffin top' is the reason why girls have so many body image issues," wrote Twitter user Alexa Morgan.

The Bad Romance singer said in 2012 that she had suffered from anorexia and bulimia since she was 15 after being criticised at that time for apparently putting on weight.

Gaga's halftime performance at the National Football League championship game between the New England Patriots and the Atlanta Falcons was a high energy medley of some of her biggest hits.

The show mixed patriotism with anthems to inclusion, and drew widespread praise.

Sales of her albums and singles soared 1,000 per cent after the show, according to NielsenMusic.

Lady Gaga sold about 150,000 digital albums and songs on Sunday, compared to about 15,000 a day prior, Nielsen said.

She also announced a US and European tour, starring in August, and will perform at the Grammys in Los Angeles on Sunday, although she is not nominated this year.