Elle Macpherson carries around a pH balance urine tester kit wherever she goes.

The 51-year-old model has admitted that the most surprising thing in her handbag is the tester kit, and she uses it to check her state of alkaline.

Elle said: ''(The most surprising thing in my handbag is) a pH balance urine tester kit to check that I'm in an alkaline state. I believe that most ailments come from having an acidic body.''

Having been labeled 'The Body' since the 1980s, Elle has had to make sure her physique is in peak condition at all times, and the 'Britain's Next Top Model' host puts her figure down to ''variation'' and ''consistency''.

Speaking to the Evening Standard newspaper, Elle said: ''Variation is key. I work out 45 minutes a day, six days a week, combining hiking, water skiing, swimming and running on a beach.

''(My idea of a healthy diet is) consistency and eating three healthy meals a day. Having said that, red meat, wheat and dairy don't work for me.''

The Australian beauty went on to talk about her love of yoga, and revealed why her favourite position is the Tree pose.

Elle said: ''(My favourite yoga position is) the Tree pose. It's about balance and I like to practice that in life as well as in yoga.''