Yet the articles bewailing muffin tops and bountiful backsides are off the mark: The fat you can see and pinch, known as subcutaneous fat, threatens your wardrobe more than it threatens your health. The real problem—visceral, or belly, fat—lies out of reach deep in the abdominal cavity, where it wreaks havoc on your health.
Big Belly, Big Problems
We tend to associate a big belly with a life well-lived, if a bit hedonistically: What would Christmas be without Santa’s jolly middle, and who can deny a die-hard sports fan his beer belly?
But while subcutaneous fat (a fatty layer of tissue that sits just beneath the skin) appears to be little more than a storage vessel for extra calories, belly fat plays a very active role in the body, releasing hormones (chemicals that direct many processes within the body) and other substances. The particular hormones that belly fat releases kick your body’s stress response into action, which raises blood pressure, blood sugar and the risk of heart disease. Down the line, high blood pressure increases your odds of having a stroke.
These hormones also make it more difficult for your body to process insulin, a hormone that controls blood sugar. As a result, people with lots of belly fat have a much higher risk for type 2 diabetes.
Additionally, these hormones increase the risk of certain kinds of cancer: People with more visceral fat have a greater chance of getting colorectal cancer and breast cancer.
Belly fat also dumps fat into the bloodstream, where it travels straight to the liver. This is especially problematic because the liver is in charge of making “good” cholesterol and “bad” cholesterol, and when it’s bombarded by fat from your abdomen, it tends to make more of the bad kind of cholesterol and less of the good.
Belly fat also takes a major toll on the brain. Some of the chemicals belly fat secretes cause inflammation, which can increase your risk of dementia and depression.
Overall, abdominal fat seems to be the main culprit behind many of the health problems traditionally pinned on obesity—and may have a larger bearing on your health than your body mass index (BMI), a more traditional measure.
Your BMI crudely assesses whether you’re overweight, at a normal weight or underweight for your height, but it doesn’t tell you where the extra pounds—and, importantly, fat—are located on your body. A study of nearly 13,000 people found that those with a normal BMI but a large waistline were 2.75 times more likely to die of cardiovascular problems, and 2.08 times more likely to die of any cause, than people with a normal BMI and a healthy waistline. The conclusion? A large waistline is a dire threat to your health—whether or not the scale says you’re in the clear.
That’s not to say you don’t have to worry if you have an elevated BMI. Many studies regarding obesity show increased health complications tied to obesity. You should follow your doctor’s advice on how to lose weight if you have an elevated BMI.
Why the Belly?
What causes you to gain belly fat rather than the more benign subcutaneous fat? Stress is a major culprit, says Kristin Speaker, MS, a doctoral candidate at the University of Colorado at Boulder, who studies the impact of stress on the body.
“Subcutaneous fat is supposed to serve as the predominant storage site for excess calories,” Speaker explains. “But with chronic stress, you get an inflammatory response in fat tissue.” This causes your fat cells to go haywire—which can drive the development of visceral obesity. Stress is a part of everyone’s life, Speaker says, but “it’s the unexpected and uncontrollable stressors that really have negative consequences—particularly in people without good coping mechanisms.” So when the going gets tough, find a way to relax, be it through meditation, exercise or time with friends and family.
While stress by itself can contribute to belly fat, one of the major problems with stress is its impact on diet. Of all the factors that lead to belly fat, “diet plays the biggest role,” Speaker emphasizes. “We’re overeating, and we’re not eating the right foods.” People who are stressed are more likely to reach for foods packed with fat and processed carbs, and to eat that food on the run—a recipe for weight gain.
There are other factors that contribute to visceral obesity. Genes, age, hormones and lifestyle habits such as smoking, drinking alcohol and physical inactivity all play a role. In particular, women should watch their waistline as they age, as estrogen—which usually encourages the body to store fat in subcutaneous stores—begins to decline. Women going through menopause often see their fat redistribute within their body. They get more belly fat, even if they aren’t gaining weight overall.
The Health Yardstick: Are You at Risk?
How can you tell whether you have too much belly fat? Grab a tape measure.
The easiest way to measure abdominal fat is to check your waistline. Relax your belly and measure your waist at the navel. Women should have a measurement under 35 inches, while men should be under 40 inches.
For a more detailed measurement, check your waist-to-hip ratio. After measuring your waist, measure your hips at their widest point (usually around your buttocks), then divide your waist size by your hip size. Women with a ratio over 0.85 and men with a ratio over 0.95 have enough abdominal fat to raise their risk of obesity-related diseases like heart disease and type 2 diabetes—even if their BMI is in a healthy range.
How to Melt Your Middle
Though visceral fat behaves differently than its subcutaneous cousin, shedding belly fat requires the same strategies you would use for any weight-loss routine: a healthy diet, scaled-down portion sizes and daily exercise.
Exercise, it seems, is particularly important: A 2007 study published in the journalNature found that exercise burned off abdominal fat faster than it burned other sources of fat. People who engaged in aerobic exercise, like brisk walking or light jogging, for at least 2.5 hours a week lost abdominal fat—and the more the participants exercised, the more belly fat they lost.
When you’re planning your workout, remember that the goal is to get your heart rate up so that you burn more calories. While it might be tempting to blast belly fat with crunches, "spot targeting" doesn’t work. It’s impossible to control where you lose fat in your body. The pounds will come from everywhere in your body, not just one particular area.
Finally, get plenty of sleep. Not only is sleep deprivation linked to weight gain and an increased risk for type 2 diabetes and high blood pressure, but sufficient sleep is crucial for keeping stress in check. “If we don’t sleep, we don’t allow our bodies to recover,” explains Speaker, “which increases the odds that stress can start having negative consequences.”