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…
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