MARY DOLAN, 38, 9st 3lb HEIGHT: 5ft 8in WAIST: 26in BMI: 19.5, healthy

markeTing and communications consultant mary is single and lives in Wimbledon, South-West London. She says: For most of my adult life I have been one of those people who can eat what they like and still stay a size eight.

Until I turned 30, friends joked that I followed a fastfood diet and yet never put on weight, and in the past my BMI indicated that I was underweight.

I eat healthily during the week and have what I like at the weekend. I run twice weekly and exercise four times a week.