By Terri Coles
TORONTO (Reuters) — There is little debate that obesity
presents a public health issue in North America — obesity
rates have more than doubled over a generation in the United
States, according to the Centers for Disease Control and
Prevention. But the causes of obesity — and therefore, the
solutions — are not as obvious, according to research
presented this week at a media workshop run by the Canadian
Institutes of Health Research.
The problem of obesity cannot be reduced simply to
genetics, the researchers said, and it also cannot be blamed
solely on our environments or learned behaviors. Media
coverage, they advised, should highlight that the obesity
epidemic is the result of a variety of factors, and that change
requires a comprehensive approach that tackles the problem from
all sides.
“Obesity’s not rocket science,” said Dr. Diane Finegood,
director of CIHR’s Institute for Nutrition, Metabolism and
Diabetes. “It’s a lot more complex.”
Biological factors like genetics or diet play a key role.
Genetics help to determine where we gain weight, said Dr.
Jean-Pierre Despres, a professor at Universite Laval in Quebec.
And where our genes tell our body to store fat — whether we’re
an apple shape that stores it on our stomachs or a pear shape
that stores it on our hips — is an important factor for
determining our cardiovascular risk, he said. Research done by
Despres and others has shown that excess fat around the stomach
– visceral fat — carries a higher risk for both diabetes and
cardiovascular disease, no matter what a person’s body mass
index is; as a result, Despres advocates for the importance of
waist circumference as a vital health measurement to be used in
conjunction with more traditional indicators of cardiovascular
risk like blood pressure and blood cholesterol measurement.
Despres described an international study he was involved
with, where 6400 doctors in 63 countries were shown how to
properly measure waist circumference in their patients. In
looking at the waist measurements and health status of 170,000
patients, the researchers found higher rates of diabetes in
those with the highest waist measurements, whether or not their
body mass index classified them as overweight or obese. “This
is really making the point that private care physicians, when
they are told and shown how to measure waist circumference, are
not measuring noise,” he said.
For someone who discovers that his or her waist is too
large, and wants to lose weight to reduce the measurement, the
solution would seem to be easy: eat less and move more.
“Obesity is the outcome of a positive energy balance,” said Dr.
Angelo Trembley, a professor at Universite Laval. But research
done by Trembley and others has shown that it may not be that
simple. A variety of biological factors that wouldn’t
automatically occur to us may also be contributing to the
dramatic rise in obesity rates, he said.
There is evidence suggesting that micronutrients —
vitamins and minerals found in food — may affect fat loss or
gain, Trembley said. For example, a study led by Trembley found
that female subjects in a placebo group couldn’t achieve
significant weight loss, despite following a carefully
restricted diet, while those who took a calcium supplement
showed better weight loss results. It’s possible that as with
glucose, the brain can recognize low levels of micronutrients
like calcium, Trembley said, and regulates appetite control in
order to correct them.
“We cannot exclude the possibility at this time that some
individuals might gain some weight due to deficiencies in some
vitamins and minerals,” he said. Continued…
