(HealthDay)—Like their neighbors to the south, Canadians are getting fat.
A new study reports that obesity rates in the country tripled in less than three decades, and estimates that more than one in five Canadians will be obese by 2019.
Researchers reviewed health surveys dating back to 1985. By 2011, they found 18 percent of Canadians were obese, up from 6 percent in 1985. People older than 40 were more likely than younger people to be overweight or obese, the researchers found. They also noted a significant increase in the percentage of severely obese Canadians.
Almost 36 percent of people in the United States are obese, meaning they have a body-mass index (BMI) of 30 or more. BMI is a measurement of body fat based on height and weight.
Obesity rates increased in all Canadian provinces, but some had larger increases than others, according to the study, which was published online March 3 in the journal CMAJ Open.
Obesity rates were lower in the west and higher in the east, with the highest rates in Newfoundland, Labrador and New Brunswick.
Obesity is categorized as class I, class II and class III, with class III being the most severe. During the study period, rates of class III obesity rose 433 percent.
"Although class I obesity appears to be increasing at a slower rate in Canada, the rate for the higher classes of obesity continue to increase disproportionately, a finding consistent with other studies," the researchers said in a journal news release.
"These results raise concern at a policy level, because people in these obesity classes are at a much higher risk of developing complex care needs," they noted.
Overall, 21 percent of Canadians will be obese by 2019, but the rates will vary from a low of nearly 16 percent in British Columbia to a high of nearly 35 percent in Newfoundland and Labrador, according to the study.
Obesity poses serious long-term health risks, such as diabetes and heart disease. The annual cost of obesity in Canada is estimated at between $4.6 billion and $7.1 billion, according to Dr. L.K. Twells, an associate professor in the School of Pharmacy and Faculty of Medicine at Memorial University in St. John's, Newfoundland, and colleagues.
The researchers said further research is needed to determine how best to reduce Canada's obesity rate and to find out why obesity rates vary so much in different parts of the country.
Explore further: Canadian adult obesity at historic high
The U.S. National Heart, Lung, and Blood Institute has more about overweight and obesity.