Data analysts at CACI analysed information from 119 local authorities in the south-east of England and found that nearly one in ten people are placing their future health at risk, even thought they are not overweight and do not smoke.
Surprisingly, they tend to eat more fresh fish and vegetables than typical Britons and are more likely to exercise.
However, experts warn that even this section of society is not immune to health problems as research found that such consumers spend nearly twice as much on wine and visit restaurants more frequently than the average person.
CACI spokesman Ian Thurman commented: "We often associate ill health with smoking, eating too much fast food and being relatively poor.
"Our findings show that a substantial section of the population do none of these things but their food and alcohol consumption is still putting their future health at risk - despite good levels of exercise."