central obesity
Carrying fat around the abdomen is more dangerous than being overweight all overUniversal Images Group/Getty Images

Scientists have found that people who weigh normal amounts but carry fat around their abdomen are at twice the risk of dying than those who are overweight or obese with an even fat distribution across their bodies. The study saw men and women with a normal body mass index (BMI) and central obesity had higher mortality risk compared with people having same similar BMI but no central obesity.

According to previously conducted research, central obesity is linked to increased overall and cardiovascular death rates. It found that extra fat in the stomach region means the area has less muscle mass, a factor that increases mortality risk and metabolic dysregulation.

"Obesity defined by BMI or measures of central obesity, such as waist-to-hip ratio (WHR) and waist circumference, is associated with increased total and cardiovascular mortality," Dr Francisco Lopez-Jimenez, a cardiologist at the Mayo Clinic, Minnesota, told Annals of Internal Medicine.

"However, a recent meta-analysis showed that being overweight according to BMI was actually associated with lower total mortality, challenging the paradigm that BMI is linked to increased mortality. Further, whether measures of fat distribution provide any incremental risk information beyond BMI alone has been a major source of controversy," he said.

The study, which was published in Annals of Internal Medicine, saw the participation of 15,184 adults aged 18 to 90. From the total subjects, about half of them were women. While for the study, body fat distribution was assessed based on anthropometric indicators alone.

"Normal-weight central obesity defined by WHR is associated with higher mortality than BMI-defined obesity, particularly in the absence of central fat distribution. Our findings suggest that persons with normal-weight central obesity may represent an important target population for lifestyle modification and other preventive strategies," he said.

He added: "Future studies should focus on identifying factors associated with the development of normal-weight central obesity and better understanding the effect of normal-weight central obesity on health outcomes. Until such data are available, the use of BMI with measures of central obesity may provide better [results] than either method [used] alone."