Do you have any studies to support this?
The studies I've found pertaining to the costs are all flawed in terms of how the conducted the tests.
When calculating the costs, they didn't break out the BMI groups they way they should have to get their stats.
From the CDC/JOEM joint study:
Results of the study revealed that within the high BMI range of 25 to 45 kg/m, medical and pharmaceutical costs were significantly higher than those whose BMI was within the normal range.
25 to 45? that's too wide of a range. That would include both a person who is 6 foot 1 & 180lbs and a person who is 5 foot 10 and 450lbs in the same group for stat purposes.
Essentially with the study they did it worked somethign like this, they took 5 morbidly obese people (450lbs) and one 180lbs person and that was one group...then they took six 170lbs people and put them in the other group.
Calculated the healthcare costs (which would obviously be higher for group A since they have 5 people who are 450lbs), and concluded that a the 180lbs person racked up 45% more in healthcare costs than the 170lbs person based on the averages of the two groups.
In an independent study done by a doctor in Norway, who was nice enough to break out the costs in to more granular BMI groups:
For persons with BMIs of 20 to 24.9 kg/m(2), mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $261
For persons with BMIs of 25 to 29.9 kg/m(2), mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $268
For persons with BMIs of 30 to 34.9 kg/m(2), mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $302
For persons with BMIs of 35 to 39.9 kg/m(2), mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $840
For persons with BMIs of 40 kg/m(2)+, mean (+/-SE) annual costs of prescription drugs, outpatient services, inpatient care, and all medical care averaged $1,189
For the CDC style study, the lumped all the green together and compared that to the blue.
However, when the groups are broken out, it tells a very different story.
Other studies (like this one
http://www.cbo.gov/sites/default/files/cbofiles/ftpdocs/118xx/doc11810/09-08-obesity_brief.pdf) have been done that conclude essentially the same thing...which is costs don't start shooting up until you hit that BMI 35 mark.
(If you were 6 foot... that would be the 265lbs mark)
According to the stats, a 6 foot person who weighed 240 actually averages less healthcare costs that a person who is 6 foot and 160.