The Duke and Duchess of Cambridge, Kate Middleton and Prince William have been married for almost a decade now. As such, reports have noted that they are now in the stage where they can throw "old married couple" jokes to each other.

In a previous report from Vanity Fair, a source shared with the publication that the duke once told his audience a joke about his wife. Based on claims, the royal stated that it is because of Kate's cooking why "he is skinny."

As revealed, it was explained that the Cambridge couple does not have their own chef inside the Kensington Palace. The reason being is that the Duchess of Cambridge does all the cooking for the family. "She loves it," the source claimed.

This was also revealed by Kate Middleton and Prince William during their appearance in Mary Berry's Christmas special episode last week. During their sit-down interview in one segment, the Duchess of Cambridge further shared that she stays up all night in the kitchen, especially when it's the kids' birthdays to bake pastries and cakes.

But, aside from the duchess, it was also unveiled that the Duke of Cambridge does similar kitchen chores as her. She added that the second-in-line to the throne used to cook for her during their university days. "He was trying to impress me," the duchess added.

Even so, she emphasized that her husband still cooks for her and the kids today. He is great with "breakfast" meals, she revealed.

As per Us WeeklyKate Middleton ensures the diet of their family. It was claimed that the duchess always prepares meals that are low in carbs and rich in lean protein ingredients. The diet was also known as the Dukan diet, which was named after its "originator," Dr. Pierre Dukan.

Normally, the diet favors raw dishes. Some of these include tabbouleh, gazpacho, ceviche, and watermelon salad. As for the duchess' favorite breakfast, it was shared that she starts her mornings with a bowl of spinach, romaine lettuce, kale, and coriander. Also, it comes with a blueberry smoothie with a dash of spirulina.

In other related news, Prince William and Kate Middleton are said to be very active up until recent times. While it was not clear as to how the Duke of Cambridge maintains his diet and figure, it has been shared that the duchess always does her yoga routines despite the busy schedule.