Heavy, but healthy. (Photo: Colourbox)

Being big isn’t always bad

New research backs up claims that many people can be obese without an increased risk of developing or dying of heart disease or cancer.

Andreas R. Graven

Published 10 September 2012 - 06:48

This was revealed in a study published online by the European Heart Journal.

The results show that a subset of fat people who have a normal and healthy metabolism have just as low a risk of serious and chronic diseases as those with normal body-mass indexes.

“In this better protected subset the heart and lungs are more functional than in others who are obese,” says researcher Francisco Ortega, who works at the University of Granada in Spain and the Karolinska Institute in Sweden.

A key factor is physical fitness, which the medical scientists charted from subjects on treadmills.

Metabolic syndrome

Despite a burden of excessive weight, these better fit persons have normal, healthy metabolisms. They show no signs of elevated blood pressure, high cholesterol or insulin resistance − alternatively diabetes.

Ortega writes that according to the research figures, as many as 30-40 percent of obese persons are healthy in this context.

People with weight problems commonly have one or more metabolic disorders – problems with the way their bodies break down foods.

As a general term, if a person has several of such symptoms, including obesity, the combination is called a metabolic syndrome.

Physical fitness as a health indicator

Ortega emphasises that the study shows, once again, how essential physical fitness is as an indicator of health.

Those who are obese and metabolically okay are in considerably better shape than others who are overweight.

“On the basis of the data we’ve collected in past years we believe that being engaged in physical activity in a varied and pleasurable way effects body organs and systems positively and makes a person healthier.”

“This applies to obese people too,” Ortega writes in a press release.

Chronic illness

Obesity and overweight obviously don’t impact everyone equally.

Some think weight reduction is necessary to bolster health and curtail illness, whereas others say you can be fat without raising your risks.

The study by Ortega and his colleagues provides ammunition for the latter:

“It’s well known that obesity is associated with a host of chronic disorders such as cardiovascular disease and cancer. Now it appears that a subset of obese people is protected against fat-related metabolic complications,” says Ortega.

“They appear to have more physical endurance than other fat people. Previously the degree by which they have a lower risk of premature death was uncertain.”

Impact on treatment

The study is based on data from 43,265 test persons accumulated from 1979 to 2003 and available for analysis.

The risks of dying of cardiovascular disease were reduced by 30-50 percent in the group of obese people who were free of metabolic disorders. Their risk was no higher than those in the normal weight category.

The researchers think these findings will be important for the treatment of obesity:

“Personnel administering treatment should bear in mind that obese people don’t all share the same prognoses and that physical fitness, the degree of fatness and metabolic indicators ought to be considered for a more accurate estimate of the individual patient’s risk of cardiovascular disease and cancer.”

“Our findings support the notion that time is much more of the essence when it comes to those who have metabolic disorders,” says the researcher.

Obesity paradox

In the same issue of the European Heart Journal, another study shows that once people have developed heart disease, those who are overweight or obese are less at risk of premature death than those of normal weight and those who are underweight.

Swedish researchers have led this study of 64,000 patients and corroborated documentation of the phenomenon known as the obesity paradox.

“Underweight patients with a BMI below 18.5 kg/m2 had a greater mortality risk − double that of the group with normal weight. Overweight people with a BMI of 26.5 - 28 kg/m2 had the lowest risk,” Oskar Angerås of the University of Gothenberg’s Sahlgrenska Academy writes in the same press release.

Researchers behind this study say no proof has been given documenting that weight loss has any positive effect on a heart patient’s prognosis after, for example, a heart attack.

They think much more research should be focused on the obesity paradox.

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Read the Norwegian version of this article at forskning.no

Translated by: Glenn Ostling