Colman 2001 - "Cost of Obesity in British Columbia"
Direct costs for obesity-related diseases cost the British Columbia health care system at least CAN$217.3 million a year (2.6% of the health care budget) in 1997. This is a very conservative estimate, so a reasonably higher estimate is $380 million, or 4.5% of the provincial health budget. Note that obesity is defined as BMI>27 for the conservative estimate and BMI>25 for the high estimate.
Using the assumption that the direct health care costs are only 45.7% of the total economic burden of illness, obesity could cost a total of $475.5 million to $831.5 million each year. At the time of writing, $830 million was 0.9% of BC's GDP.
Method: The author uses Birmingham's method of population attributable fractions applied to the BC population and 1997 medical costs.