Bariatric treatments for adult obesity - Institute of Health Economics

eport their height and under-report their weight. 1,16,17,29,31,88,97 The directly measured weight andheight data suggest that in Canada the prevalence of obesity (BMI ≥ 30 kg/m 2 ) in the householdpopulation aged 18 and older (excluding pregnant women) is growing steadily and has almostdoubled during the past several decades. 11,16,17,29,47,94 Whereas individuals with obesity accounted foronly 13.8% of Canada’s adult population in 1978–1979, this figure was 23.1% in 2004. 11,17,29,47Among men, the rates increased from 7.9% in 1970 to 22.9% in 2004 and for women, the ratesincreased from 12.9% in 1970 to 22.5% in 2004. 16The increase was evident in each of the three obesity categories, especially in classes II and III. 11,29The proportion of adults in class II increased from 2.3% in 1978–1979 to 5.1% in 2004 and in classIII from 0.9% to 2.7%. The obesity rate rose during this period for every age group except amongthose aged 65 to 74. The most striking increases were among people younger than age 35 and thoseaged 75 or older. The percentage of obese adults aged 25 to 34 more than doubled (from 8.5% in1978–1979 to 20.5% in 2004). The increase among people aged 75 or older was about the same:from 10.6% to 23.6%.Although the difference in the 2004 directly measured obesity rates between men and women wassmall, it was larger for class III obese adults (1.6% for men and 3.8% for women). 11,16,17,29,47 For bothgenders, rates were lowest among those aged 18 to 24 (10.7% of men and 12.1% of women) andpeaked at around 30% among those aged 45 to 64. The percentage of seniors who were classified asobese was about 25%.Statistics Canada recently released the latest data from the Canadian Community Health Survey(CCHS), based on a survey of more than 65,000 Canadians, conducted between January 2007 andDecember 2007 (www.statcan.gc.ca/daily-quotidien/080618/dq080618a-eng.htm). 88,98 Overall, 17%of Canadians aged 18 or older self-reported data on weight and height that classified them as obese(BMI > 30 kg.m 2 ). 88,98 Although self-reported obesity rates generally changed little between 2005 and2007, during that period there was a slight increase in the proportion of women aged 18 to 24 whowere considered obese. Self-reported obesity rates were generally highest among individuals aged 45to 64. Twenty per cent of men in this age group were considered obese, as were 18% of women.Men aged 25 to 44 were considerably more likely than their female counterparts to be obese.Extrapolating from self-reported and directly measured data collected over time, it has beenestimated that the actual prevalence of adult obesity is likely closer to 25%. 88 If historical trendsremain unchanged, prevalence could reach 27% for men and 24% for women by 2010. 16 The WHOprojected that obesity prevalence in Canada will increase between 2005 and 2015 by 4.3% for menand 6.3% for women. 16Factors influencing adult obesity prevalence in CanadaObesity in Canada is influenced by numerous individual-level and environmental factors, such as age,gender, ethnicity, income, and place of residence. 1,11,12,28,29,47,88,89 Directly measured and self-reportedobesity rates for both men and women seem to increase until individuals reach the age of 65, afterwhich the rates start to decline.Canadians are experiencing accelerated weight gain at younger ages 1,8-12,29,31,32,47,94,95 and it seems thatobesity among children and adolescents in Canada is advancing at an even more rapid pace thanobesity among adults. 1,3,8,47,94 According to directly measured BMI data from the 2004 CCHS, in 2004,among children and adolescents (aged 2 to 17), one in four (26%) were overweight or obese (18.1%were overweight and 8.2% were obese). 1,94 The obesity rate has increased during the past decadesBariatric treatments for adult obesity – March 2012 10