WINNIPEG - Couch potatoes take heart.
A study from the University of Manitoba has found people who carry just a bit of extra weight are no more likely to have serious health problems or die prematurely than their slimmer peers.
Researchers at the Manitoba Centre of Health Policy, which conducts studies for the provincial government, used weight and height information from two decades of national health surveys to determine body mass index. They then used the information to divide people according to whether they were "normal," simply "overweight" or actually "obese" and studied their health outcomes.
Those in the overweight category and even those who were on the lower end of the obese category didn't have more health problems and didn't die sooner. Being overweight may not be as dangerous as previously thought, the study concluded.
"The people in the overweight group don't really seem to be at much risk at all," said lead researcher Randy Fransoo. "It might just be that the threshold for when trouble really starts is closer to the obese group than the overweight group."
The study found that, as with the rest of the country, the number of obese people in Manitoba is on the rise. One in four Manitobans is now considered obese.
But Fransoo said that doesn't necessarily mean the health-care system will be swamped by heavy patients.
The study found that overweight people — those with a body mass index of between 25 to 29.9 — were not much more likely to visit the doctor's office than slimmer patients. And, he said, they had the same mortality rate as those with "normal" weight.
"It was really just the obese group that had the higher risk of mortality in our study."
Even within the obese population, Fransoo said there seemed to be varying degrees of risk. Those who were just slightly obese — with a body mass index closer to 30 — generally seemed otherwise healthy.
The study found dangerous health problems developed once people inched closer to a body mass index of 35 or higher.
Body mass index is a calculation that uses your height and weight to estimate how much body fat you have. A BMI between 18.5 and 24.9 is considered healthy.
Obesity itself doesn't cause premature death, but the study found it is related to heart disease, stroke, high blood pressure and diabetes — all of which can cause serious health problems or lead to death. Obese people with an extremely high body mass index are therefore more likely to take a toll on the health-care system.
Although some slightly overweight people might see the study as a good reason not to start dieting or buy a gym membership, Fransoo said there are still risks with carrying just a little extra weight. People generally gain weight as they age, so they can easily inch into the obese category and increase their health risks.
"If you're in that overweight group, it's not like you have a clear slate for the rest of your life and there is a guarantee of no trouble," Fransoo said. "You still have to be careful and you still want to do what you can to make sure you're not getting into that obese category."
Arya Sharma, chair in obesity research and management at the University of Alberta, said studies such as the Manitoba one highlight that there is no such thing as "ideal weight." Some people who carry a few extra pounds can be completely healthy while others can develop health problems, he said.
And sometimes those suffering from health problems related to weight actually have a history of dieting and gaining the weight back, he said.
"If you do have extra weight but don't have any of those health problems . . . then losing weight might not be good for you," Sharma said. "It might lead you on that path of yo-yo dieting."
Not surprisingly, the Manitoba study found those who are sedentary are more likely to be overweight.
But researchers also found that even those who were active in their spare time were more likely to be overweight if they spent their days sitting at a computer or at a desk for more than 30 hours a week. The key to staying healthy seems to be getting away from the computer screen and getting regular activity, Fransoo said.
"Even if you're active in your leisure time, it's still better to not be sedentary if that's what your day job is," he said. "Maybe take the bus to work and do a little walking. Maybe get off a stop or two earlier ... It seems to be working in as much casual activity as you can during your daily life."
Still, some who work with bariatric patients say studies such as this one shouldn't sway either a doctor or a patient.
Yoni Freedhoff, medical director of the Bariatric Medical Institute in Ottawa, said weight is a personal issue and there are a lot of factors to take into account. He said just because a person's weight doesn't pose a health risk, doesn't mean it doesn't have an impact.
"There are huge degrees of weight bias in society," Freedhoff said. "It's the last socially acceptable form of discrimination. We know it can and does impact on things like promotion, education, schoolyard bullying."