The TV presenter had the operation in Belgium on Friday.
The gastric band will restrict Vanessa, 48, from consuming more than 1,000 calories a day.
'I feel it's a shame I've had to do it,' she explains. 'I wish I'd had the self-control and willpower to do it on my own...
'I feel like it was the last resort. I didn't have it in me to do it all by myself again.'
Vanessa's weight has fluctuated over the past 10 years as she's struggled to stick to her diets.
'At the moment I'm a size 18 - 20 but I'd like to be nearer to a size 12,' she tells OK!
'Then Cheryl Cole and I would look identical - you wouldn't be able to tell us apart. I could be her body double!'
Where to next?
- Gastric band surgery: the facts
- Find a diet to help you lose weight
- Tips on beating obesity
- Fern Britton talks about her gastric band surgery
- 10 extreme diets