German supermodel Heidi Klum is battling hard to get back in shape after gaining weight while she was pregnant with daughter Lou, whom she gave birth to three weeks ago.

The 'Victoria's Secret' model who is married to singer Seal admits she has struggled more to get back into shape now than she did after having her other children, reported Contactmusic.

"I wouldn't say I'm back in shape yet. Everything changes when you get older. It was different when I was 31 with the first one and now being 36 with the fourth one," Klum said.

The 36-year-old TV star has now cut back on her diet and has hit the treadmill to tone her figure fearing she will remain bigger forever if she doesn't act now.

"I think that if you wait too long and it sticks there it stays that way forever. I have to be motivated," Klum added.