NHS data reveals Derbyshire County PCT was one of the country’s main health bodies to provide weight-loss surgery during 2011 and 2012.
Forty-seven people in every 100,000 had operations such as gastric bands and stomach-stapling under the PCT, which ceased to exist earlier this year after a Government reorganisation.
Tam Fry, of the National Obesity Forum, said: “These figures are totally shocking but it is not surprising in any way.
“We have been trying to cope with obesity in the last 15 years but we have done nothing but stand up and watch the rates go up and up.”
Derbyshire County Council, which now deals with combating obesity, has pledged a range of measures to tackle the problem.
A council spokesman said: “We have a comprehensive approach to tackling obesity, which is prioritised in the Derbyshire Health and Wellbeing Strategy.
“Each year about £1.3m is spent on activities and programmes to help local people adopt or maintain a healthy lifestyle.”
The spokesman pointed to fitness-boosting programmes such as the Village Games and Walking for Health projects as well as the Derbyshire Healthy Lifestyle Hub which offers support to help people change their lives.
According to the NHS figures, Derby City PCT had the highest proportion of patients needing weight-reduction surgery – with 80 people out of every 100,000 going under the knife.