Research from the US, published in the British Journal of Sports Medicine, has shown high levels of white blood cells - markers of inflammation - in the blood of overweight and obese men. Lack of fitness also contributes to the inflammatory condition. High levels of white blood cells are also linked to coronary artery disease.
The 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.
