Question: I've heard that excess body fat concentrated around the middle of my body increases my risk of disease.Is that true, and if so, why?
Midsection is dangerous
area for fat buildup
Answer: Yes, it's true.As a general rule, men tend to accumulate fat around their middle ("apple" shape), which accounts for the higher incidence of heart attacks in men.Overweight women, on the other hand, tend to be "pear shaped," storing their fat in their hips and thighs.
Although it's still not healthy to be carrying excess fat, men and women who carry it lower down are at less risk for disease and premature death, than those who store it in their abdomens.
In a word, the reason that fat around the middle is much more dangerous is that this upper body fat is less stable and it moves into the bloodstream easily.
Fat cells all look alike under a microscope, but curiously enough, they behave quite differently depending on where in the body they're stored.Fat stored in the abdomen and chest areas has several unique properties.These fat cells contain high levels of an enzyme called lipoprotein lipase.Lipoprotein lipase enables upper body fat cells to store more energy (calories), when an excess of calories (food) is ingested.Since these fat cells are designed to store more calories, they automatically get larger faster.And once fat starts to accumulate around the waist, the process, by its own chemical nature, accelerates.
In contrast, fat cells stored in the buttocks and legs contain less lipoprotein lipase.As a result, these cells enlarge more slowly, but unfortunately they also shrink at a slower rate, which makes it harder to lose weight from the legs and buttocks.
Another important difference between abdominal fat and fat cells from other areas of the body is in the way they respond to hormones.
Abdominal fat is more responsive to the stress hormone adrenaline, which causes the release of free fatty acids into the bloodstream.Once in the bloodstream, these fats are carried directly to the liver, where they interfere with the normal breakdown of insulin.Over time, high insulin levels make the body less responsive to insulin and insulin resistance develops.This contributes greatly to the risk of diabetes.
In addition to interfering with insulin breakdown, those same free fatty acids stimulate the liver to overproduce triglycerides.
Triglycerides are blood fats that increase a person's risk of heart disease.Insulin also acts as a growth factor, which may explain the link between abdominal obesity and certain cancers.
As if that weren't enough, upper body fat cells also contain an excess of an enzyme that activates the hormone cortisone.Cortisone is another potential contributor to diabetes and hypertension, and hypertension is a risk factor in both stroke and heart disease.Also, abdominal fat is clearly associated with high levels of the bad type of cholesterol (LDL), which is a major risk factor in high blood pressure, stroke and heart disease.
Upper body fat also builds up internally, where it can't be seen, surrounding the internal organs.It can accumulate to the point where it interferes with the expansion and contraction of the lungs, making breathing difficult.If it's hard to breathe, it's impossible to be active.An inactive lifestyle further enhances the body's tendency to store fat.It becomes one big vicious circle.
So what can a person do to break out of this circle? Get up, get moving, eat healthier and eat less.
Stephenie Karony is a certified health
and fitness instructor, a personal trainer and the author of
"Body Shaping with Free Weights." Send questions to her at
P.O. Box 262, Wailuku Hi. Her column appears on Wednesdays.