The Duchess of Cambridge reportedly adds spirulina to her breakfast smoothie every morning.

Duchess Catherine

Duchess Catherine

The 35-year-old royal - who has three-year-old son Prince George and two-year-old daughter Princess Catherine with her husband the Duke of Cambridge - is believed to sprinkle a touch of the microalgae, which is super high in protein, to her morning juice, according to Marie Claire UK.

The brunette beauty's breakfast drink is believed to be made up of kale, spinach, romaine lettuce, coriander, blueberries and the powder in a bid to kick-start her metabolism and to ensure she consumes the important vitamins and nutrients.

And Duchess Catherine - who was formerly known as Kate Middleton before she married Prince William - has made it known she is a dab-hand in the kitchen and enjoys rustling up new recipes and making her own curry and chutneys at home.

Speaking previously about her concoctions for the royal family, Catherine said: "I can remember being at Sandringham, for the first time, at Christmas. And I was worried what to give the Queen as her Christmas present. I was thinking, 'Gosh, what should I give her?'

"I thought, 'I'll make her something.' Which could have gone horribly wrong. But I decided to make my granny's recipe of chutney. I was slightly worried about it, but I noticed the next day that it was on the table.

"I think such a simple gesture went such a long way for me and I've noticed since she's done that on lots of occasions and I think it just shows her thoughtfulness, really, and her care in looking after everybody."

And the Palace Chef has also revealed Catherine does "a lot of the cooking".

Speaking previously Carolyn Robb said: "Kate does quite a lot of the cooking at the moment. You have to remember that she's not royal. She comes from a normal background and a normal home where she's always cooked for herself."