Physical appearance is not the only reason to lose belly fat. Excess abdominal fat, also called visceral fat, may make you susceptible to diabetes, heart disease, sleep apnea, stroke and certain types of cancers, says the staff at MayoClinic.com. Belly fat often accumulates unexpectedly. Understanding what causes excess belly fat may help you control it.
Testosterone and Menopause
Testosterone is a male hormone that is present in small amounts in women, but reduced during menopause. This hormone is responsible for revving up metabolism and increasing lean muscle mass, says women's health specialists on the Epigee website. An April 2000 study published in the "Journal of Obesity" found that men with low testosterone levels have increased visceral fat. Menopausal women with reduced testosterone levels are also affected. Lead author Imke Janssen of Rush University studied 359 menopausal women between the ages of 42 and 60. Her research team measured fat in the abdominal cavity and performed blood tests to assess levels of testosterone and estrogen. Janssen reported that the amount of active testosterone in the body was the strongest belly fat predictor. Estrogen levels and age did not correlate with the amount of abdominal fat.
Neuropeptide Y
Your existing belly fat may create a Catch-22 scenario, reports researchers from the University of Toronto, in an article on the Science Daily website. Dr. Yaiping Yang and his colleagues identified a hormone called neuropeptide Y, which is produced in visceral fat tissue. Scientists once believed that this hunger-stimulating hormone was only produced in the brain, but Dr. Yang and his team discovered that it is also produced locally in your abdominal fat. While fat cells cannot self-replicate, neuropeptide Y increases fat cell number by stimulating fat cell precursor cells, which eventually evolve into abdominal fat cells. The extra fat cells stimulate more neuropeptide Y and create a vicious hunger and weight gain cycle.
Weight Gain
Increasing fatty food consumption while decreasing your activity level usually leads to weight gain. If you are a guy, there's a good chance that this extra fat will take the express route to your belly, says exercise physiologist Len Kravitz of the University of New Mexico. While women have gynoid, or pear-shaped, bodies, which accumulate fat around the hips and thighs, men have android, or apple-shaped, bodies, which accumulate belly fat. In fact, researchers at UT Southwestern Medical Center, in a study conducted on male and female rats, reported that male and female fat cells are genetically dissimilar, which may explain the different fat distribution patterns among men and women.
Stress
A stressful life has serious health repercussions. The production of the stress hormone cortisol is an example. Cortisol produces the "fight or flight" situation associated with stressful situations. People with Cushing's disease, characterized by excess cortisol in the bloodstream, tend to have excess body fat, reports the "Harvard University Gazette." Cortisol works in conjunction with insulin to create abdominal fat, says Elissa Epel, assistant psychology professor at the University of California in San Francisco. In an article on the university's website, Epel explains that cortisol compounds the problem by creating cravings for high-fat, high-sugar foods.
References
- Rush Univeristy Medical Center; Increase in Visceral Fat During Menopause Linked With Testosterone; August 2009
- University of New Mexico; Gender Differences in Fat Metabolism; Chantal Vella, M.S. and Len Kravitz, Ph.D
- UT Southwestern Medical Center; Belly Fat or Hip Fat-It Really is All in Your Genes; May 2010
- "Science Daily"; Your Belly Fat Could Be Making You Hungrier; April 2008
- "Harvard Gazette": Single Enzyme May be Linked to Obesity; December 2001
- Univeristy of California; Big Belly May be a Matter of Stress; January 2007
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