Britain's Sarah Ferguson felt like she was "drowning in food" before she lost 42lbs.
The Duchess of York decided to drop the extra pounds after realising she was close to the weight she was when she was heavily pregnant with her first child Princess Beatrice 25 years ago.
She told HELLO! magazine: "Beatrice was an 8lb 8oz baby and I was only 6lb off my full-blown pregnancy weight. I decided to make a change. I used to be so angry - I believed that I had lost control. I couldn't fit into any of my clothes.
"I was just drowning in eating, drowning in food. It took courage to go out in public in all the years I have been overweight."
The 54-year-old royal - who was 224 pounds at her heaviest - took part in a gruelling daily boot camp session on a Swiss mountain resort, and managed to drop the weight in just five months.
She has also cut out sugar and maintained a healthy diet.
Meanwhile, the flame-haired beauty - who was once an ambassador for Weight Watchers - has become an official envoy for the Institute of Global Health Innovation at Imperial College London.
She said: "I want to help combat obesity."
Tagged in Sarah Ferguson Princess Beatrice