Kate Middleton is too thin for some people.

The Duchess of Cambridge is already a mom of three, but she never gained too much weight following her pregnancies. She was able to maintain her pre-baby figure.

One netizen took to Quora to ask why Middleton stays so thin. The same user wondered what the duchess’ diet is.

According to Deanna Eppers, Middleton used to follow the Dukan diet days before her royal wedding to Prince William. It remains unknown if she still follows that diet, but she does follow a clean and healthy diet plan.

Middleton’s breakfast is usually green smoothie or muesli with fruits on top. Her lunch is a green salad with lean protein, like chicken or salmon. For dinner, the duchess typically eats roasted vegetables with more lean protein.

Also, Prince William’s wife doesn’t snack. Instead, she drinks a lot of water and some unsweetened tea.

“She eats very clean and exercises on a daily basis. She is also a very competitive in sports,” Cathy Snyder wrote.

Meanwhile, according to a report from Daily Mail, Middleton employs rowing and cycling exercises into her workouts. She focuses on her abs with the help of a Swiss gym ball. She also finds time to run as often as possible when in Norfolk. Sometimes ,she runs with Charlotte in her buggy or with their dog, Lupo, by her side.

Also, just like her sister-in-law Meghan Markle, Middleton reportedly loves yoga.

“While Kate's workout routine is obviously rigorous, the Duchess of Cambridge is also said to enjoy yoga—which helps her calm down and de-stress, as well as building up strength and core muscles,” Harper’s Bazaar reported.

“The benefits of daily yoga practice needs, so it's unsurprising that Kate employs it to stay trim.”

The netizens have different opinions about Middleton’s weight. Some find the duchess too thin and are already concerned for her health. They fear that she might have an eating disorder like Princess Diana.

For others, Middleton’s weight just suits her height and age. Also, they say there is nothing to worry about Prince William’s wife because she is healthy and is capable of doing things she has to do. Others say that Middleton is not thin, she’s just lean.

Kate Middleton
Kate Middleton during a State Banquet at Buckingham Palace on Oct. 23, 2018 in London. Getty Images/John Stillwell.