London, Oct 18 : Being obese can raise illness risk as it negatively impacts body's internal chemistry, a new research has shown.
Researchers from United States found that levels of white blood cells were highest in men who were unfit and overweight. White blood cells are key to fighting infection, but high levels can be a sign of inflammation, which is linked to coronary heart disease.
To reach the conclusion, a team from the Pennington Biomedical Research Center carried out tests on 452 healthy men who were taking part in a long-term study of fitness.
Blood tests were taken, and analysed for their content of various types of white blood cell.
After taking account of age, the researchers found that all groups of white blood cell were lowest in the men who were most physically fit.
The greater proportion of body fat a man had, the higher his white blood cell count was. Total white cell count was highest in men who had a combination of higher body fat and lower levels of physical fitness.
Levels were also high among men with lower body weight but lower levels of fitness.
However, a high degree of physical fitness negated the effect of extra body fat. Lead researcher Professor Tim Church said it was clear that inflammation played a key role in heart disease and other illnesses, but the factors which drove it were still relatively unclear.
"There is nothing worse than a risk factor that an individual cannot modify, but here are two risk factors - obesity and fitness - which they can do something about," BBC quoted him, as saying.
June Davison, cardiac nurse at the British Heart Foundation, said: "These findings add to evidence that regular physical activity and keeping close to a healthy weight have huge benefits for your heart health."
The study has been published in the British Journal of Sports Medicine.