Forget about apples and oranges. When it comes to body shape and longevity, it’s more helpful to compare apples and pears. That’s the message of a study published in the journal PLOS ONE that found that pear-shaped people, who have comparatively thinner waists than people shaped like apples, tend to live longer.
To reach their conclusion, researchers measured the waist-to-height ratio of almost 7,500 people in the UK between 1985 and 2005. They compared the data to US studies that used body mass index (BMI), and discovered that keeping your waistline to less than half your height predicted you would live longer. What’s more, they suggested that waist-to-height ratio was a more accurate predictor of longevity than BMI.
How BMI can fool you
BMI has been used as a measure of health since the 19th century, and it’s a much more complicated calculation than waist-to-height ratio. To get it, you have to multiply your weight in pounds by 703, divide by your height in inches, then divide that number by your height in inches again.
- Between 18.5 to 24.9 are healthy
- Below 18.5 means you’re underweight
- Between 25 and 29.9 are overweight
- Between 30 and 39.9 are obese
- 40 and over are extremely obese
The problem is, BMI doesn’t take muscle mass into account, which can put someone into the overweight or obese categories even if he or she isn’t carrying extra fat. It also neglects to measure belly fat, which means a larger waistline and may be particularly dangerous for your heart.
Why you need to watch your waistline
A 2010 study of nearly 105,000 people, published in JAMA Internal Medicine, suggested that people with larger waistlines (more than 47 inches for men and 43 inches for women) were twice as likely to die during the study period than people with smaller waistlines (less than 35 inches in men and less than 30 inches in women). Bigger waists are also associated with insulin resistance, type 2 diabetes, inflammation, cholesterol problems and coronary heart disease.
Researchers aren’t exactly sure what makes belly fat so dangerous, but it may have something to do with how fat is distributed throughout your body. If you’re pear shaped, your fat is located mostly in your lower half; it’s also subcutaneous, meaning it sits right under the skin. People who are apple-shaped have more fat in their abdomen. That fat, called visceral fat, is deeper and collects around the organs. Researchers think visceral fat produces chemicals that lead to inflammation, a culprit in heart disease and cancer.
What you can do
Targeted fat loss, sometimes called “spot reduction,” is a myth; there’s no way to eliminate belly fat on its own. So, while sit-ups may give you rock-hard abs, they’ll still be buried under layers of fat.
Instead, you can lose fat all over, and the best way to do that is to keep your diet in check. The good news is that visceral fat goes away comparatively more easily than subcutaneous fat, and getting rid of it can lower your blood pressure and cholesterol levels.
Weight loss is a simple formula: If you burn more calories than you eat, you lose weight. For example, a Big Mac has 540 calories. You could walk briskly for more than an hour to work that off, or you can just skip the Big Mac.