No matter what your body shape, excess fat is not good for your health. But when it comes to body fat, location counts, and each year brings new evidence that the fat lying deep within the abdomen is more perilous than the fat you can pinch with your fingers.
In most people, about 90% of body fat is subcutaneous, the kind that lies in a layer just beneath the skin. If you poke your belly (the pinchable stuff!), the fat that feels soft is subcutaneous fat. The remaining 10% — called visceral or intra-abdominal fat — lies out of reach, beneath the firm abdominal wall. It's found in the spaces surrounding the liver, intestines, and other organs.
It's also stored in the omentum, an apron-like flap of tissue that lies under the belly muscles and blankets the intestines. The omentum gets harder and thicker as it fills with fat.
Although visceral fat makes up only a small proportion of body fat, it's a key player in a variety of health problems.
As women go through their middle years, their proportion of fat to body weight tends to increase — more than it does in men — and fat storage begins favoring the upper body over the hips and thighs. Even if you don't actually gain weight, your waistline can grow by inches as visceral fat pushes out against the abdominal wall.
The trouble with visceral fat
Body fat, or adipose tissue, was once regarded as little more than a storage depot for fat blobs waiting passively to be used for energy. But research has shown that fat cells — particularly visceral fat cells — are biologically active. "One of the most important developments [since the mid-1990s] is the realization that the fat cell is an endocrine organ, secreting hormones and other molecules that have far-reaching effects on other tissues," says Dr. Barbara B. Kahn, chief of the division of endocrinology, diabetes, and metabolism at the Beth Israel Deaconess Medical Center in Boston.
Before researchers recognized that fat acts as an endocrine gland, they thought that the main risk of visceral fat was influencing the production of cholesterol by releasing free fatty acids into the bloodstream and liver. We now know that there's far more to the story. Researchers have identified a host of chemicals that link visceral fat to a surprisingly wide variety of diseases.
Subcutaneous fat produces a higher proportion of beneficial molecules, and visceral fat a higher proportion of molecules with potentially deleterious health effects. Visceral fat makes more of the proteins called cytokines, which can trigger low-level inflammation, a risk factor for heart disease and other chronic conditions. It also produces a precursor to angiotensin, a protein that causes blood vessels to constrict and blood pressure to rise.
Researchers at Harvard have discovered that, compared with subcutaneous fat, visceral fat secretes more of retinol-binding protein 4 (RBP4), a molecule that increases insulin resistance. As the volume of visceral fat increases, so do levels of RBP4. The connection is so strong that researchers are developing a blood test for RBP4 as a way for physicians to measure an individual's store of visceral fat.
Subcutaneous fat produces more of certain beneficial molecules, including the hormone leptin, which acts on the brain to suppress appetite and burn stored fat. Adiponectin, another hormone produced mainly by subcutaneous fat, helps protect against diabetes by regulating the processing of fats and sugars; it also has an anti-inflammatory effect on the linings of blood vessels. (Adiponectin is made by visceral fat, too, but production falls as fat volume increases.)
More than skin deep
While calculating body mass index (BMI) is a helpful tool to assess the overall health of an individual’s weight, determining a waist-to-hip ratio with a measuring tape is a better method to pinpoint belly fat. Calculate waist-to-hip ratio by dividing the waist’s circumference at its narrowest point (use the belly button as a guide) by the hips’ circumference at their widest points (near the top of the bony protrusions). Ratios of 0.8 and below are healthy, and those above 0.8 suggest an increased risk for heart disease and diabetes.
Some studies have found waist circumference to be a better determinant and to better express the amount of belly fat present.
Ready to battle the bulge?
Thankfully, visceral fat responds to the same diet and exercise strategies that can help you shed pounds and lower your total body fat.
Your weight is largely determined by how you balance the calories you eat with the energy you burn. Overeating and lack of physical activity are the main reasons why people pack on excess pounds. However, aging also can contribute to weight gain as well as to an increase in body fat. That’s because as you age, you gradually lose muscle and fat accounts for a greater percentage of your weight. Less muscle mass also leads to a decrease in the rate at which your body uses calories, which can make it more challenging to lose or stay at the same weight.
Therefore, trim the fat with the four pillars of a healthy middle: exercise, diet, sleep, and stress management.
While core exercises such as the plank and crunches will firm up abs, they won't blast the belly fat that lies underneath. Instead, try moderate or vigorous intensity aerobic activity. Complement aerobics with diets low in saturated fat, cholesterol, and carbohydrates (beer lovers, beware), and consider protein-rich meals and low-fat snacks.
And don’t forget to manage life stressors and catch plenty of Zzzs — increased cortisol levels (the stress hormone) and lack of sleep are both tied to abdominal weight gain.
Belly (aka visceral) fat can be more harmful than other types in terms of leading to bigger health issues. But the good news is that it also surrenders more easily to improved fitness and diet than other types!
It's also stored in the omentum, an apron-like flap of tissue that lies under the belly muscles and blankets the intestines. The omentum gets harder and thicker as it fills with fat.
Although visceral fat makes up only a small proportion of body fat, it's a key player in a variety of health problems.
As women go through their middle years, their proportion of fat to body weight tends to increase — more than it does in men — and fat storage begins favoring the upper body over the hips and thighs. Even if you don't actually gain weight, your waistline can grow by inches as visceral fat pushes out against the abdominal wall.
The trouble with visceral fat
Body fat, or adipose tissue, was once regarded as little more than a storage depot for fat blobs waiting passively to be used for energy. But research has shown that fat cells — particularly visceral fat cells — are biologically active. "One of the most important developments [since the mid-1990s] is the realization that the fat cell is an endocrine organ, secreting hormones and other molecules that have far-reaching effects on other tissues," says Dr. Barbara B. Kahn, chief of the division of endocrinology, diabetes, and metabolism at the Beth Israel Deaconess Medical Center in Boston.
Before researchers recognized that fat acts as an endocrine gland, they thought that the main risk of visceral fat was influencing the production of cholesterol by releasing free fatty acids into the bloodstream and liver. We now know that there's far more to the story. Researchers have identified a host of chemicals that link visceral fat to a surprisingly wide variety of diseases.
Subcutaneous fat produces a higher proportion of beneficial molecules, and visceral fat a higher proportion of molecules with potentially deleterious health effects. Visceral fat makes more of the proteins called cytokines, which can trigger low-level inflammation, a risk factor for heart disease and other chronic conditions. It also produces a precursor to angiotensin, a protein that causes blood vessels to constrict and blood pressure to rise.
Researchers at Harvard have discovered that, compared with subcutaneous fat, visceral fat secretes more of retinol-binding protein 4 (RBP4), a molecule that increases insulin resistance. As the volume of visceral fat increases, so do levels of RBP4. The connection is so strong that researchers are developing a blood test for RBP4 as a way for physicians to measure an individual's store of visceral fat.
Subcutaneous fat produces more of certain beneficial molecules, including the hormone leptin, which acts on the brain to suppress appetite and burn stored fat. Adiponectin, another hormone produced mainly by subcutaneous fat, helps protect against diabetes by regulating the processing of fats and sugars; it also has an anti-inflammatory effect on the linings of blood vessels. (Adiponectin is made by visceral fat, too, but production falls as fat volume increases.)
More than skin deep
While calculating body mass index (BMI) is a helpful tool to assess the overall health of an individual’s weight, determining a waist-to-hip ratio with a measuring tape is a better method to pinpoint belly fat. Calculate waist-to-hip ratio by dividing the waist’s circumference at its narrowest point (use the belly button as a guide) by the hips’ circumference at their widest points (near the top of the bony protrusions). Ratios of 0.8 and below are healthy, and those above 0.8 suggest an increased risk for heart disease and diabetes.
Some studies have found waist circumference to be a better determinant and to better express the amount of belly fat present.
Ready to battle the bulge?
Thankfully, visceral fat responds to the same diet and exercise strategies that can help you shed pounds and lower your total body fat.
Your weight is largely determined by how you balance the calories you eat with the energy you burn. Overeating and lack of physical activity are the main reasons why people pack on excess pounds. However, aging also can contribute to weight gain as well as to an increase in body fat. That’s because as you age, you gradually lose muscle and fat accounts for a greater percentage of your weight. Less muscle mass also leads to a decrease in the rate at which your body uses calories, which can make it more challenging to lose or stay at the same weight.
Therefore, trim the fat with the four pillars of a healthy middle: exercise, diet, sleep, and stress management.
While core exercises such as the plank and crunches will firm up abs, they won't blast the belly fat that lies underneath. Instead, try moderate or vigorous intensity aerobic activity. Complement aerobics with diets low in saturated fat, cholesterol, and carbohydrates (beer lovers, beware), and consider protein-rich meals and low-fat snacks.
And don’t forget to manage life stressors and catch plenty of Zzzs — increased cortisol levels (the stress hormone) and lack of sleep are both tied to abdominal weight gain.
Belly (aka visceral) fat can be more harmful than other types in terms of leading to bigger health issues. But the good news is that it also surrenders more easily to improved fitness and diet than other types!
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