Kate Middleton, Royal Duchess of Cambridge, has recently surprised everyone with her post-baby flat-stomach. Does she follow some weight-loss regime to help her look the way she did three months after her delivery? Middleton was spotted at SportsAid Athlete Workshop in London's Queen Elizabeth Olympic Park showing off her volleyball skills.

Her fat-free tummy caught the attention of everyone and were in awe with her toned stomach and svelte figure while she enjoys playing and seemed so natural when she moved.

Middleton carried off a sporty yet royal look. She was wearing a classic blue and white striped Ralph Lauren top and J Brand Jeans. To complete her elegant look, she teamed her attire with a navy Smythe jacket and Russell and Bromley wedges.

Since the time the news has surfaced, royal duchess' post-baby weight-loss secrets were being speculated. Her post-baby flat-stomach-look in three months after delivery has led to frenzied talks.

Weight Loss Secret 1

Sunday People claimed Middleton's post-baby weight-loss involves the post-natal fitness regime provided by fitness expert Judy Di Fiore.

It's the expert's book, "The Complete Guide to Postnatal Fitness," that may have assisted the royal duchess to bring back her amazing shape. The book is like a bible for new mothers. It described the bodily changes of mothers during pregnancy and suggested some simple abdominal exercises to build up muscles and reduce fat overtime. It has been described as an "intellectual read."

In one of her interviews, Di Fiore asked mothers not rush the process of attaining pre-baby body. One should enjoy and embrace motherhood.

Weight Loss Secret 2

Some even speculated that the royal duchess' post-baby weight-loss is the complex Dukan diet. According to some unknown sources, Middleton acquired this shape after losing weight by breastfeeding and consuming a portion-controlled diet. This speculation is being accompanied by her well-monitored diet with a regular practice of yoga.

Emma Sayle, Middleton's long-time close friend from college, said the royal duchess had put on only about 29 pounds during her pregnancy as she regularly worked out and maintained good eating habits.

She also disclosed that Middleton aimed at staying fit by doing Pilates and swimming while she was still pregnant. With her doctor's advice she started with long walks and yoga.

So we have quite a lot for Middleton's secrets to post-baby weight-loss. You can adopt them diligently and acquire the royal look.

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CREDITS: Youtube.com/The Telegraph