More than half of adults in the Royal Borough have been labelled overweight or obese in a shock new report - but still have trimmer waistlines than the national average.
It said the figures were collated using data from Sport England and based on self-reported information on people's height and weight collected since 2012.
It is the first time data of this type, worked out from Body Mass Index (BMI), has been produced.
Of the eight local authorities in the Thames Valley, the borough is the second slimmest behind Reading.
It also comes in significantly lower than the national average of 64 per cent.
The highest rate in the region is in Bracknell Forest (66.2 per cent), followed by West Berkshire and Buckinghamshire.
Dr Adrian Hayter, the chairman of the Windsor, Ascot & Maidenhead Clinical Commissioning Group (CCG), says obesity in adults can often be attributed to childhood habits.
He said: "In our diets we have a lot of sugar and we know it is bad. Simple things can be done like cutting out sugary drinks."
"The amount of sugar in those drinks is huge and is setting children up for obesity."
Dr Hayter, who is also a GP at Newton Court Medical Centre in Old Windsor, sees a large number of patients who have early joint disease and require hip and knee surgery.
He added: "Some of those problems are caused by obesity."
Cllr David Coppinger, cabinet member for adult services and health at the Royal Borough believes the statistics are 'comparatively low' and therefore indicates healthy lifestyles.
He added: "We want to continue to encourage residents to be more active and eat healthily to prevent the risk of developing diabetes or heart disease."
Until now, modelled estimates of adult obesity were based on demographic studies of local areas and not on data based on individuals.
Public Health England was not able to provide the numbers its percentages were based on.
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