The type of belly fat that lies deep within the abdomen that surrounds internal organs, also known as visceral fat, is a known danger to health. Now a new study is showing it could be worse than previously thought because of its link to muscle and bone loss.
This latest study on visceral fat, which was published in the American Journal of Clinical Nutrition, is interesting because the findings directly oppose the well-accepted belief that obesity is actually a protective factor against accelerated loss of bone and muscle mass.
Heavier individuals require more muscle and bone strength to support their bodies, so muscle and bone density might be expected to increase with increased body fat. But instead, the researchers noted that as visceral fat stores increased in study subjects, bone and muscle density went down.
To reach these unexpected conclusions, scientists at the University of Michigan looked at CAT scans imaging the vertebrae of 7,230 patients between the ages of 18 and 65. They then compared BMI (a measure of body weight compared to height), and levels of subcutaneous fat (the kind of fat just below the skin) and visceral fat to the subjects’ thickness of vertebral bone and spinal muscle.
Although higher BMIs and subcutaneous fat levels were each tied to less dense spinal bone and muscle, this relationship was even stronger for visceral fat. According to the scientists, “this finding is interesting because it may support the notion that excess fat in the intra-abdominal region has a negative, pathophysiologic influence on local muscle and bone.”
The knowledge that visceral fat is a danger to health is not new. Scientists have long known that visceral fat can engage in “cellular cross-talk” with organs throughout the body, fueling the fire of inflammation and increasing the susceptibility toward some chronic diseases. But the idea that there might be a specific communication between muscle, bone, and fat that disrupts normal muscle and bone growth and function is a fairly new concept.
In addition to visceral fat’s ability to wreak havoc throughout the body, one of the things that makes it most dangerous is that it is invisible to the eye. Excess stores can lie undetected around the organs of people who are even normal weight. But a sedentary lifestyle, overeating, the aging process, and obesity together may all contribute toward accumulation of visceral fat.
Fortunately, excess visceral fat accumulation can be prevented through proper diet and lifestyle.
Zhang P, Peterson M, Su GL, Wang, SC. Visceral adiposity is negatively associated with bone density and muscle attenuation. Am J Clin Nutr. First published November 26, 2014, doi: 10.3945/ajcn.113.081778.