En español | It's not your imagination. That band of fat currently making it harder to zip up your favorite jeans is very likely to expand as you age, for men and women alike.
But while no one relishes a spare tire, there's something especially noxious about this particular type of waistline weight gain. Turns out, belly fat is not like other fat, and experts say that what should really concern you is its proximity to the major organs in your midsection.
Located in the abdominal cavity, this “visceral” fat — as opposed to the body's subcutaneous fat, which you can pinch between your fingers — is linked to a slew of health problems.
"Visceral fat coats some of your internal organs and hangs down like an apron from your large intestine,” says gastroenterologist Samuel Klein, chief of the Division of Geriatrics and Nutritional Science at Washington University School of Medicine in St. Louis. “It's associated with an increased risk of metabolic diseases, including insulin resistance, high blood pressure, diabetes, cardiovascular disease and fatty liver disease.”
Although researchers first studied visceral fat and metabolic disturbances back in the 1950s, no one paid much attention to the work until the obesity epidemic started gaining speed. Now, studies are multiplying that show that the more visceral fat you have, the greater your risk for things like breast and colorectal cancers.
People with the greatest amount of this deep abdominal fat are nearly three times as likely to develop dementia as those with the least of it, according to a study by the Kaiser Permanente Division of Research, which followed study participants for more than three decades.
How abdominal fat harms
Besides wrecking your waistline, the problem with abdominal fat is that its cells pump out chemicals that promote disease. “Fat is not just a depot to store energy,” Klein says. “It's a very active endocrine organ that produces hormones, inflammatory proteins and fatty acids and secretes them into the bloodstream."
Visceral fat may be more harmful because it's closer to the body's portal vein, which transports blood from the intestines to the liver. Chemicals secreted by visceral fat travel to the liver, where they can affect cholesterol levels and other disease processes. “Visceral fat could be very important in the development of or the cause of fatty liver disease,” Klein says.
By contrast, the subcutaneous fat on your hips, upper thighs and arms is considered relatively harmless. But recent research suggests that subcutaneous fat located elsewhere on the body may be more risky.
"There's a growing consensus that there are three different types of fat depots — visceral fat, lower-body subcutaneous fat and upper-body subcutaneous fat,” says Deborah Clegg, a visiting professor at Cedars-Sinai Medical Center in Los Angeles. “The upper subcutaneous fat may be as bad as the visceral fat.” An example is a roll of fat on the torso around the bra line; any fat on your arms isn't included as this type of “upper” fat.
Data from a long-running study involving more than 2,300 people showed that a greater volume of upper-body subcutaneous fat is linked to higher body mass index (BMI), blood pressure, fasting blood glucose and levels of triglycerides — a dangerous type of blood fat — as well as lower “good” HDL cholesterol. But more research is needed to confirm the connection, experts say.
How much visceral fat are you harboring? There isn't an easy way to find out, but measuring your waist an inch or two above your hip bones will give you a clue.
Women whose waists measure 35 inches or more and men with a waist measurement of 40 inches or more may have a dangerous amount of visceral fat. “It's a crude index, but it's not a bad idea to measure your waist over time to watch for changes,” Klein says.
Your shape provides better clues to your health than your overall size. People who are pear-shaped tend to fare better than those who are shaped like apples — they naturally accrue more fat in the abdomen.
Women are generally protected from visceral fat and its harms in their reproductive years, but the steep decline in estrogen at menopause can result in a less healthy silhouette. “As they transition through menopause, some women start to deposit more fat in the visceral depot, and they're the women that then have an increased risk of disease,” Clegg says.
You don't have to be obese to court the health problems associated with abdominal fat. New data shows that women carrying more fat around their middle had a higher risk of succumbing to an early death from any cause than those with more fat around the hips and thighs, even when women were of normal weight.
How to attack it
To banish visceral fat, you need to lose weight by eating less and exercising. The good news? Researchers think that visceral fat seems to be the first type of weight to go when people lose weight. (In terms of gaining weight, the reverse is true. As Clegg notes, people tend to gain the subcutaneous kind of weight first. But when that “depot” is full, they put on visceral weight.)
Although losing weight generally is the only way to get rid of visceral fat, exercise does have a small independent effect.
A change in what you eat could also help. When Italian researchers recruited volunteers to consume locally produced, unprocessed foods or food from the supermarket for six months, those on the unprocessed food regimen had less visceral fat, along with better blood pressure and fasting glucose levels.
Because stress hormones like cortisol can encourage the accumulation of abdominal fat, mindfulness and yoga may also help reverse the trend.
"But weight loss is really the most important thing,” says Klein. “You don't have to become lean, but losing a little bit of weight, even if you're still obese, can have important benefits if you can keep the weight off long term."