I coined that phrase. Dontcha love it? What I’m
talking about is the increasingly common “beer belly” on men of a certain age
-- men who look nine months pregnant before the baby has “dropped:” A high,
hard abdomen, which is actually your peritoneal cavity filled with visceral fat
around your organs. Your jacket button doesn’t button any more. You can’t hug
without first bumping into the huggee. I know. I was “there” once, before I
lost 170 pounds.
I first came across the noun form “omentum” about
2005 in, “You on a Diet,” a book by a Canadian doctor, Michael Roizen, popularized
by Oprah and a PBS series. The omentum is a
sheet of fat that is covered by the peritoneum. The greater omentum is attached
to the bottom edge of the stomach, and hangs down in front of the intestines. The
other edge attaches to the transverse colon. The lesser omentum is attached to
the top edge of the stomach, and extends to the undersurface of the liver. In
humans, especially men who make bad food choices, the omentum is a mass of fat
around and especially in front of the stomach, liver, spleen, pancreas, kidneys
and intestines.
This “visceral fat, also known as organ fat or
intra-abdominal fat, is located inside the peritoneal cavity, packed in between
internal organs and torso. It is differentiated from subcutaneous fat which is
underneath the skin, and intra-muscular fat which is interspersed in skeletal
muscle. Other distinctly different types of body fat include bone marrow fat and
epicardial fat, which is deposited around the heart and found to be a
metabolically active organ.
The common understanding of obesity is a net
energy imbalance. The fundamental cause of obesity, however, is a metabolic
disorder of fat regulation. There is a growing consensus that, in humans,
central obesity is related to the excessive consumption of fructose. It is also
associated with elevated levels of the hormone insulin. In a large study
(NHANES III), excessive waist circumference appears to be more of a risk factor
for metabolic syndrome than BMI (Body Mass Index). The Central Obesity Index
(CBI) is another measure more predictive of increased risk than BMI.
Central obesity is associated with a
statistically higher risk of heart disease, hypertension, insulin resistance,
and Type II diabetes. Belly fat is a symptom of Metabolic Syndrome. (Scroll
down to see Retrospective #9). Central obesity is also associated with glucose
intolerance and dyslipidemia (“high cholesterol”), as well as a group of
diseases that are either inherited or due to secondary causes (Cushing’s syndrome,
PCOS, and treatment for AIDS).
Central obesity is known to predispose
individuals for insulin resistance and Type 2 diabetes. Discoveries in recent
decades have revealed that abdominal fat is especially active hormonally,
secreting a group of hormones called adipokines that may possibly impair
glucose tolerance. Central obesity seems to be the foremost type of fat deposit
contributing to rising levels of serum resistin, one such hormone. Conversely,
serum resistin levels have been found to decline with weight loss, especially
decreased central obesity. Central obesity is metabolically very unhealthy!
Of course, there are sex differences in fat
accumulation. Female sex hormones cause fat to be stored in the buttocks, hips
and thighs. Men are more likely to have fat stored in the belly. When a woman
reaches menopause and estrogen production declines, fat migrates from the
buttocks, hips and thighs to the waist and belly.
So, what can be done about “omental adiposity”?
Low fat and restricted calorie diets have not
proven to be an effective long-term intervention. Most people regain the
weight that was lost and many regain still more. Spot exercises, such as
sit-ups, crunches and other abdominal exercises are useful in building abdominal
muscles, but they have little, if any, effect on the adipose tissue located there.
And, just for the record, there is little evidence that beer drinkers are more
prone to abdominal adiposity than non-drinkers or drinkers of wine or spirits.
The best way to lose
and keep off excess omental weight – the “pot belly” – is a diet that provides
satiety (a high fat diet), that digests slowly and restores skeletal muscle
(moderate protein), and that allows
you to burn body fat for energy. That diet is a low carbohydrate diet. See Retrospective #11 (scroll down), or, on
Facebook, search my Time Line. After the body burns the “sugars” (glucose) in
carbs for energy, it turns to fat for energy, both dietary and body fat. I
know. I’ve regained some of the 170 pounds that I lost, but I have lost my
“beer belly” forever.
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