Gisele Bundchen thinks a law should be made to make new mothers breastfeed for at least six months.

The 30-year-old supermodel - who gave birth to son Benjamin, her first child with husband Tom Brady, in December 2009 - thinks it is wrong for mothers to give formula to their newborns.

She said in an interview with Harper's Bazaar magazine: "Some people think they don't have to breastfeed and I think, 'Are you going to give chemical food to your child when they are so little?' I think there should be a worldwide law that mothers should breast-feed their babies for six months."

The Brazilian-born beauty also admitted that "breastfeeding really helped me keep my figure".

Gisele also revealed she prepared "mentally and physically" by doing yoga before her home birth.

She said: "It prepared me mentally and physically. It's called 'labour', not 'holiday' for a reason and I knew that. You want to go into the most intense physical experience of your life unprepared? That doesn't make sense to me. I wasn't expecting someone else to get the baby out of me."

Gisele - who delivered Benjamin in the bathtub at her and Tom's Beacon Hill Penthouse, in Boston - doesn't think she is special for opting for a home birth, she just thought it was normal.

She said: "Not for one second did it cross my mind that I was not going to have my baby at home. I'm not the first person to give birth naturally. Billions of other women have come before me and have done this - so why can't I do it?"