The TV presenter said that slimming down from a size 14 to a 12 for this year's London Marathon helped her feel "more energetic and confident" about herself.
"I feel much better when I’m this size, it's lovely to be able to go to a shop and buy a size 12," she told Closer magazine.
"I feel more energetic and confident. It's taken me until the age of 50 to feel really happy in my body, which is extraordinary when you think about it. I'm never going to be über-thin, it's not how I'm meant to be, but I feel good the size I am."
Kelly admitted that remaining in shape would be a "challenge", but claimed that the support of her husband Steve Smith and daughter Rosie would be crucial.
"I'm more organised about what I eat now. I'll always have a banana in my bag and I plan my meals properly," she said. "I've cut down on sweets, too. I'm not banning them, but I'll have more fruit around and I make sure that Rosie, has a plate of fruit to snack on instead of crisps and
