In a series on celebrities and their health the BBC News website talks to diet and fitness expert Rosemary Conley about how gallstones inspired her 'Hip and Thigh diet'.
'I ate fat for Britain'
Mrs Conley, aged 49, has written nearly 30 books, presented as many fitness videos and has her own range of fitness clubs, a magazine and an online slimming club.
In 2004 she was made a commander of the British Empire (CBE) for her services to the fitness and diet industries.
She has appeared regularly on TV and has her own range of low fat foods. In December 2001 she became the only woman ever to be granted the Freedom of the City of Leicester.
HOW DID YOU FIRST REALISE SOMETHING WAS WRONG?
It was in about 1986 when I felt a pain in my kidneys.
I felt so sick that I went to see the doctor. I kept fainting. They said I would have to go to the hospital.
HOW DID YOU GET DIAGNOSED?
When I got to the hospital they said it was gallstones and they would have to be taken out, but they said I would need to plan about 10 weeks' recovery time.
I could not afford to have the time off as I was closing a business at the time.
The doctors said that if I ate a low-fat diet I could help myself. They said it would not cure the gallstones, but that it would make things better.
So I created my own low-fat diet and found that I lost half a stone.
It all went from my hip and thighs and I realised that this was due to my low fat eating.
The members of my slimming club saw how I was looking and said they wanted to try it and this was how I started the hip and thigh diet.
WHAT WAS YOUR REACTION TO THE DIAGNOSIS?
I was totally ignorant about what gallstones were. I did not know what they were or how they were affecting me, but I knew I had to change my eating habits. I had been eating fat for Britain.
I used to have far too much butter and cream on things. When I had a bowl of fruit salad I used to drain off the fruit juice so that I could fit in more cream and when I had a piece of bread I used to have as much butter on as I had bread.
When I was little and staying at my granny's she would give me cornflakes and cream.
I had lost weight and kept it stable at around eight and a half stones, but when I started the low-fat diet I went to eight stones without a problem.
WHAT WAS YOUR TREATMENT?
They examined my gallstones by putting some special fluid into me and then doing an ultrasound.
I was then on medication for the next five years which helped and they said that if I kept off the fats and took the medication I would be OK, but that if I carried on eating the fatty foods that I would become very ill.
In 1993 I decided to have my gallbladder removed and they did it by key-hole surgery.
In just seven years they had gone from me facing the prospect of a 12-inch scar to getting the gallbladder removed through my belly button.
After the operation they gave me a jar with the stones in to show what they looked like and a video showing me what I was like inside.
I was back in work in a few days and without this awful cloud hanging over me about what would happen if I ate the wrong thing.
I am still eating low-fat food, but now the incentive is to keep lean.
HOW DID YOU FEEL DURING TREATMENT?
Providing I kept on low-fat foods I was alright and after the operation I was fine.
My gallstones were not huge but you would not have wanted to pass them through your body.
HOW DO YOU FEEL NOW?
I feel absolutely great. I have never looked back. I think through what I have learned about the low-fat foods I have been able to help a lot of other people.
WHAT IS YOUR MESSAGE TO OTHER PEOPLE WITH THE SAME CONDITION?
I think if you are diagnosed with gallstones it depends on your condition whether you need to get them removed, but the keyhole surgery was amazing and my recovery was very quick.
Eating low fat, though, is a good way to cope in the meantime. It does not make the stones go away but it does help ease the pain.