Obesity is now considered a global epidemic by the World Health Organization. In Canada, the prevalence of obesity among men and women has increased steadily in recent decades and is projected to continue to increase.1,2 Recent data from Statistics Canada using measured body mass index (BMI) in adults 18 years and older estimated that 39.4% of Canadian males were overweight (BMI 25-<30 kg/m2) and 28.7% were obese (BMI ≥30 kg/m2) in 2015.3 Similarly, 29.7% of Canadian females were overweight while 24.7% were obese. Obesity is associated with multiple comorbidities, including type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, cardiovascular disease, stroke, cancer (colorectal, prostate, endometrial, breast, etc.) and sleep apnea, amongst others.4,5 Associations with premature death have also been observed.6 In 2006, the annual costs associated with overweight and obesity in Canada were estimated to be $6 billion in direct costs (66% attributable to obesity) and $5 billion in indirect costs, which represent 4.1% and 4.2% of the total direct health and total health expenditures in Canada, respectively.7 Additional Canadian estimates have ranged between annual costs of $1.27-11.08 billion.8 Obesity has traditionally been considered a result of lifestyle factors, including poor diet and physical inactivity, and thus, it has been considered a preventable condition. However, the Canadian Medical Association has recently declared obesity to be a chronic medical disease due to the associated negative health effects.9 While lifestyle modifications can prevent obesity in some, further pharmaceutical intervention is required to mitigate the growing obesity epidemic in Canada and reduce the national burden of disease.

Alberta’s Tomorrow Project

Alberta’s Tomorrow Project (ATP) is an ongoing, population-based, longitudinal study consisting of 55,000 Albertans aged 35-69 years old.10,11 Established in 2000, ATP is Alberta’s largest health research study that aims to establish risk factors for cancer and other chronic diseases. Study participants completed questionnaires on demographic information, health/medical history, and lifestyle factors including physical activity and diet. Anthropometric measures, such as self-reported height, weight, and hip/waist circumference have also been collected from all participants. Additionally, a subset of over 30,000 patients have had their physical measurements objectively measured by study staff at a study centre, including body fat percentage. Study recruitment continued until 2015, with questionnaires administered throughout, such that the type and number of surveys completed by each participant is dependent on when they joined ATP (Figure 1). Repeated measures have, and will, be obtained over the course of the study duration (50 years) through periodic follow-up surveys. Table 1 summarizes the number of participants who completed each survey (baseline and follow-up). Height and weight information is currently not routinely captured in administrative data in Alberta. Furthermore, it has been over a decade since a cohort for an obesity study has been identified in Alberta, and thus, the prevalence and patient characteristics of obesity have not been well-defined in Alberta. Data from this research collaboration with ATP can be used in the proposed Research Study to estimate the burden of illness of obesity in Alberta. Figure 1: Evolution of the Alberta’s Tomorrow Project, Study Enrolment and Questionnaires. Image Source. Table 1: Summary Table of Survey Completions in the Alberta’s Tomorrow Project Cohort [table id=2 /] (1) The values represented here reflect number of participants who completed all three questionnaires (HLQ, CDHQ-I, and PYTPAQ). If you are only interested in using HLQ and CDHQ-I together or HLQ and PYTPAQ together, the numbers will be very similar to the three questionnaires combined. This is because similar numbers of participants completed the CDHQ-I and/or PYTPAQ. (2) The values represented here reflect number of participants who completed HLQ and Survey 2004 or HLQ and Survey 2008. If you are interested in using only Survey 2004 or Survey 2008 alone, the numbers will be very similar to the combined questionnaires. This is because Survey 2004 and Survey 2008 were only sent to participants who had already completed the HLQ.

References

1.     Bancej C, Jayabalasingham B, Wall RW, et al. Trends and projections of obesity among Canadians. Health Promotion and Chronic Disease Prevention in Canada : Research, Policy and Practice 2015; 35(7): 109-12.
2.     Twells LK, Gregory DM, Reddigan J, Midodzi WK. Current and predicted prevalence of obesity in Canada: a trend analysis. CMAJ Open 2014; 2(1): E18-E26.
3.     Statistics Canada. Table  13-10-0794-01 Measured adult body mass index (BMI) (World Health Organization classification), by age group and sex, Canada and provinces, Canadian Community Health Survey – Nutrition. 2017.  (accessed June 13 2018).
4.     Khaodhiar L, McCowen KC, Blackburn GL. Obesity and its comorbid conditions. Clinical cornerstone 1999; 2(3): 17-31.
5.     Guh DP, Zhang W, Bansback N, Amarsi Z, Birmingham CL, Anis AH. The incidence of co-morbidities related to obesity and overweight: A systematic review and meta-analysis. BMC Public Health 2009; 9: 88-.
6.     Katzmarzyk PT, Ardern CI. Overweight and obesity mortality trends in Canada, 1985-2000. Canadian journal of public health = Revue canadienne de sante publique 2004; 95(1): 16-20.
7.     Anis AH, Zhang W, Bansback N, Guh DP, Amarsi Z, Birmingham CL. Obesity and overweight in Canada: an updated cost-of-illness study. Obesity reviews : an official journal of the International Association for the Study of Obesity 2010; 11(1): 31-40.
8.     Tran BX, Nair AV, Kuhle S, Ohinmaa A, Veugelers PJ. Cost analyses of obesity in Canada: scope, quality, and implications. Cost Effectiveness and Resource Allocation : C/E 2013; 11: 3-.
9.     Canadian Medical Association. CMA recognizes obesity as a disease. 2015. https://www.cma.ca/En/Pages/cma-recognizes-obesity-as-a-disease.aspx (accessed June 13 2018).
10.   Robson PJ, Solbak NM, Haig TR, et al. Design, methods and demographics from phase I of Alberta’s Tomorrow Project cohort: a prospective cohort profile. CMAJ open 2016; 4(3): E515-E27.
11.   Ye M, Robson PJ, Eurich DT, Vena JE, Xu JY, Johnson JA. Cohort Profile: Alberta’s Tomorrow Project. International journal of epidemiology 2017; 46(4): 1097-8l.