(CNN) -- It's more bad news for America's growing waistline: Excess belly fat is associated with a higher risk of early death from any cause, regardless of how much overall body fat you have, a new study finds.
In women, each 10-centimeter increase in belly fat raised the risk of death from any cause by 8%. For men, each 10-centimeter increase in girth raised the risk of by 12%.
The better news: Larger hips and thighs are associated with a lower risk of early death, according to the study published by the The BMJ on Wednesday. That may be due to a protective effect that fat on those areas provide toward higher cholesterol and blood sugar levels, according to prior studies.
Those findings are a result of an analysis of 72 studies involving more than 2.5 million participants who were studied from three to 24 years. All of the studies explored various measures of weight around the middle of the body, long thought to be a significant risk factor for metabolic resistance, which is a precursor to diabetes, heart disease and more.
"Our results suggest that measures of central adiposity (fat) could be used as a supplementary approach, in combination with body mass index, to determine the risk of premature death," the authors said.
The role of belly fat
Most measurements of weight focus on the body mass index or BMI, which takes your weight in kilograms and divides it by the square of your height in meters. (there are online tools you can use to calculate your BMI).
If your BMI is less than 18.5, you're considered underweight. Your weight is considered normal if your BMI falls between 18.5 and 24.9. You are deemed overweight when your BMI is between 25 and 29.9 -- over 30 BMI indicates you are obese.
But critics point out that BMI doesn't differentiate between lean body mass and fat mass and doesn't give an indication of where the fat resides. That's a problem because existing evidence suggests more fat around the middle -- and abdominal fat often known as "beer bellies" in men and belly fat in women -- are more associated with chronic disease than an overall rating of obesity.
Here's why the fat around the middle is so dangerous. Too much belly fat points to a buildup of a unique type of fat, called visceral fat, around various internal organs, such as the liver, pancreas and intestines.
Visceral fat is called 'active fat' because it affects hormone function by secreting a protein that leads to an increased resistance to insulin, thus setting us up for type 2 diabetes, high blood pressure, excess cholesterol, heart disease, some cancers and Alzheimer's disease.
Visceral fat is different from the pinchable fat we see in our arms, legs, thighs and "love handles" on the hips. That's called subcutaneous fat, which doesn't affect hormones.
Besides eating too much and exercising too little, just why does belly fat occur? Scientists think cortisol, the stress hormone, may play a role -- cortisol increases insulin resistance, which adds to fat deposits.
Do you have excess belly fat?
To tell if you have potentially dangerous abdominal fat, take out a soft tape measure. Then, while standing straight with a relaxed stomach (no sucking in allowed), measure your tummy a few inches above your hips.
Are you in belly fat danger? For women, the key figure is thought to be 35 or more inches (89 centimeters) around the stomach, for men it's 40 inches (102 centimeters).
What to do?
Doing crunches isn't going to melt visceral fat; that will only tone your abs.
Diet and exercise, however, seem to be better at tackling visceral fat than subcutaneous fat.
You need to make sure you have more calories going out than calories in to make that happen -- by either limiting your calorie intake or exercising more:
- Focus on a plant-based diet full of fresh or frozen veggies and fruits
- Choose lean sources of protein and low-fat dairy products
- Eat only whole grains -- not processed cereals, breads, muffins and the like
- Cut back on sugar -- avoid processed cakes, cookies and sugar-sweetened beverages
- Watch your portion sizes (Tip: use a salad plate instead of a dinner plate)
- Add muscle strengthening and weight training to your routine. Muscle burns more calories than fat.
- Jump start exercise by doing moderate aerobics, such as brisk walking, for at least 150 minutes a week or vigorous aerobic activity, such as running, fast biking, swimming or team sports, for at least 75 minutes a week
Tip: Use the talk test to check your level of intensity, suggests the US Centers for Disease Control and Prevention. Can you talk but not sing? Then you're exercising at a moderate level. Can't say more than a few words without stopping to take a breath? You're doing a vigorous exercise.
You may not see the results on the scale, so experts suggest taking a waist measurement before you begin your war on belly fat and measuring periodically to check. You may find inches dropping off your waist before your hips -- and that's a good thing.