Obesity rates across Canada are at alarming levels and continuing to climb, according to a new paper in the Canadian Journal of Public Health, which provides the first comprehensive look at adult obesity rates across Canada since 1998 - complete with "obesity maps."

The Maritimes and the two Territories had the highest obesity rates from 2000 to 2011 – more than 30 percent of the population in those regions is estimated to be obese. British Columbia had the lowest overall rates, but obesity still increased from less than 20 percent to almost 25 percent. Rates in Quebec remained below 24 percent.

Using data from the Canadian Community Health Survey, the researchers adjusted self-reported Body Mass Index (BMI) data to get more accurate obesity estimates. Over the 11-year study period, the researchers found the greatest increase occurring between 2000 and 2007.

"Being obese or overweight significantly increases the risk of chronic illnesses, such as heart disease, diabetes, and some cancers," says study lead author, Prof. Carolyn Gotay in the University of British Columbia's School of Population and Public Health. "Our analysis shows that more Canadians are obese than ever before – on average, between one fourth and one third of Canadians are obese, depending on the region."

The obesity maps that accompany the study serve as a tool to regional authorities to monitor and act on these trends. "Maps that use colours and well-known geographical depictions are an efficient way to convey complex data that transcends language differences and personalizes the data for the viewer," says Gotay. "This information can provide an impetus for action for the public, health care providers, and decision makers."