January 27, 2014

Obesity in Michigan: Impact and Opportunity

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CHRT Issue Brief January 2014

For over a decade, Michigan has had one of the highest rates of obesity in the nation.1 Although obesity was just recently recognized as a disease by the American Medical Association, clinicians have long understood that obesity is associated with major health risks and is a driver of health care costs.2 But do all individuals categorized as obese face the same health issues? This study of privately insured individuals in Michigan makes clear that those who are categorized as severely obese face much greater health challenges and place higher demands on the health care system than those in other weight categories.

In this analysis, we report rates of moderate and severe obesity in a large commercially insured population—adults covered by Blue Cross Blue Shield of Michigan (BCBSM)—and link claims data and health risk assessment data to identify specific differences in disease burden and health care costs.

Key Points:

  • Approximately 21 percent of this BCBSM study population was moderately obese in 2010, and 14 percent were severely obese. Combined, 35 percent of this population was obese, a rate similar to other state and national estimates.
    • Even though severely obese individuals made up only 14 percent of the total study sample, this group accounted for one-quarter of total annual health care costs of the total group studied.
    • Severely obese individuals had average annual health care costs of $7,117, an amount 50 to 90 percent higher than costs for all other weight groups in this study.
  • Severely obese people have a significantly higher disease burden than those who are moderately obese.
    • Those with severe obesity were 1.25 to 3 times more likely to have a serious chronic condition than those who were moderately obese.
    • The severely obese were also 50 percent more likely to have three or more comorbid conditions compared to moderately obese individuals.
  • In terms of interventions to reduce obesity, many are suggested, but two have evidence behind them: bariatric surgery and intensive behavioral therapy (a type of ongoing patient counseling).

1 Centers for Disease Control and Prevention (CDC). Behavioral Risk Factor Surveillance System Survey Data. Atlanta, Georgia: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 1995-2012.

2 American Medical Association. June 18, 2013. Press Release: AMA Adopts New Policies on Second Day of Voting at Annual Meeting. http://www.amaassn.org/ama/pub/news/news/2013/2013-06-18-new-ama-policies-annualmeeting.page (accessed 10/7/13).

Obesity in the Privately Insured Population in Michigan


In this study population of 29,691 privately insured adults,3 more than one-third were categorized as obese, with 21 percent categorized as moderately obese and 14 percent as severely obese, similar to national trends.4,5,6 Figure 1

Figure 1
Prevalence of Weight Categories, BCBSM, 2010

Figure 1

Source: BCBSM Special Data Request

Disease Burden

Those in the study population with higher BMI had higher rates of disease. In particular, severely obese individuals were far more likely than healthy weight individuals to have one of the following 14 conditions commonly comorbid with obesity: asthma, back pain, coronary artery disease, cancer, congestive heart failure, chronic obstructive pulmonary disease, depression, type 2 diabetes, gallbladder disease, acid reflux, hyperlipidemia, hypertension, osteoarthritis, and sleep apnea.7

The rates of cardiovascular and metabolic conditions (such as coronary artery disease and hypertension) were consistently and markedly higher among those who were severely obese compared to those with lower BMI categories. In general, the chances of having such a condition increased in a step-wise fashion as BMI increased. Figure 2

Figure 2
Prevalence of Cardio-Metabolic Conditions in the Severely Obese compared to Other Weight Categories, by Condition, BCBSM, 2010

Figure 2

Source: BCBSM Special Data Request

The most striking difference in comorbidity prevalence rates was for type 2 diabetes. Specifically, 9.5 percent of moderately obese individuals had a diagnosis of type 2 diabetes compared to 19 percent of severely obese individuals. That is, severely obese individuals were twice as likely to have this serious chronic condition as those who were moderately obese. Increased BMI was also associated with having more than one chronic condition. Overall, 20 percent of the severely obese individuals had two chronic conditions and 20 percent had three or more, making this group two to four times more likely than healthy weight individuals to have multiple comorbidities. Compared to those with moderate obesity, severely obese individuals were nearly 50 percent more likely to have three or more conditions, further highlighting the stark difference in disease burden between those who are moderately and those who are severely obese. Figure 3

Figure 3
Proportion of the Severely Obese with Multiple Comorbid Conditions compared to Other Weight Categories, by Number of Conditions, BCBSM, 2010

Figure 3

Source: BCBSM Special Data Request

Health Care Costs

Total annual health care costs for this BCBSM study population were approximately $135 million in 2010. As expected, severely obese members had significantly higher overall costs and accounted for a disproportionately high percentage of overall costs, undoubtedly driven by significantly higher rates of chronic disease. While the severely obese were only 14 percent of the total study population, they accounted for nearly one-quarter of total annual health care costs. Figure 4

Figure 4
Percentage of Study Population and Total Annual Health Care Costs, by Weight Category, BCBSM, 2010

Figure 4

Source: BCBSM Special Data Request

On average, severely obese individuals in this study population had annual health care costs of $7,117, which was 50 percent greater than costs for the moderately obese and 90 percent greater than costs for those with healthy weight. Conversely, costs for moderately obese individuals were only 16 percent higher than costs for overweight individuals. In terms of health care costs, being moderately obese was more like being overweight and less like being severely obese. Figure 5

Figure 5
Average Annual Health Care Costs per Person, by Weight Category, BCBSM, 2010

Figure 5

Source: BCBSM Special Data Request

Weight Management

The people in our study population indicated significant motivation to reduce their weight (contrary to some physicians’ perceptions8,9,10,11). Approximately 50 percent of severely obese individuals in our study reported actively trying to manage their weight, the same proportion as the moderately obese. Furthermore, over one-third in both categories reported feeling confident that they could improve their weight management. Figure 6

Figure 6
Proportion Actively Trying to Manage Weight and Confident They Can Improve Weight Management, by Obesity Category, BCBSM, 2010

Figure 6

Source: BCBSM Special Data Request

3 All data in this report reflect claims and health risk assessment data for 29,691 BCBSM commercially insured adults aged 18 or older and who were continuously enrolled and lived in Michigan in 2010.

4 Weight categories were defined by calculating body mass index (BMI), a ratio of weight to height (measured in kg/m2). See the Methodology & Definitions section for a description of weight categories and their corresponding BMI ranges.

5 Corresponding data tables can be found in the Appendix.

6 Percentages may not total to 100 percent due to rounding.

7 See Table A-2 for prevalence rates of the 14 conditions by weight category.

8 V. Forman-Hoffman, A. Little, and T. Wahls. June 6, 2006. Barriers to obesity management: a pilot study of primary care clinicians. BMC Family Practice 7(35). http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1525170/pdf/1471-2296-7-35.pdf (accessed 10/1/13).

9 C.A. Befort, K.A. Greiner, et al. October 2006. Weight-Related Perceptions among Patients and Physicians: How Well Do Physicians Judge Patients’ Motivation to Lose Weight? Journal of General Internal Medicine 21(10): 1086–1090. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1831634/ (accessed 10/1/13).

10 J.S. Briscoe, and J.A. Berry. March 2009. Barriers to Weight Loss Counseling. The Journal for Nurse Practitioners 5(3):161–167.

11 J.M. Ferrante, A.K. Piasecki, P.A. Ohman-Strickland, and B.F. Crabtree. September 2009. Family Physicians’ Practices and Attitudes Regarding Care of Extremely Obese Patients. Obesity 17(9): 1710–1716.

Effective Interventions for the Severely Obese

Given that many individuals are motivated to reduce their weight, it is crucial for physicians to identify and employ effective obesity interventions. Although the topic of obesity is not new to medical or public health discourse, there is still confusion about what interventions for treatment and prevention actually work. There are many interventions that have popular support, but that do not yet have research support indicating that they are effective at reducing obesity on a sustained basis. It is clear, however, that two medical interventions work to reduce obesity: bariatric surgery and intensive behavior therapy.

Bariatric Surgery

Bariatric surgery12 is one of the only treatments proven to reduce body weight by 20 to 60 percent, and long-term studies show that those going through the surgery can maintain weight reductions over 20 years.13,14 Bariatric surgery is specifically geared toward severely obese individuals who have a BMI greater than 40 or a BMI above 35 with one or more comorbid conditions. All candidates must also have documentation from a physician that non-surgical interventions have failed.15 Despite its proven effectiveness, it is estimated that only about 0.6 percent of clinically eligible adults underwent bariatric surgery nationally in 200216 and, in this BCBSM study population, the incidence of bariatric surgery among potentially clinically eligible adults was slightly higher at 1.2 percent.17,18

Intensive Behavioral Therapy for Obesity

Until recently, there has been little evidence that primary-care-based interventions effectively treat obese patients or help them maintain weight loss. However, in 2012, the U.S. Preventive Services Task Force (USPSTF) concluded that intensive behavioral therapy (IBT), a type of patient counseling, is the most effective non-surgical approach to weight loss. The USPSTF recommended that for patients with a BMI of 30 or greater, primary-care providers either provide IBT or refer patients to others who provide this service. Based on a meta-analysis of randomized controlled trials, the USPSTF found that 12 to 26 brief, physician-delivered, IBT19 sessions per year could produce significant reductions in weight (an average 6 percent reduction) for obese persons.20,21 As a result of the USPSTF recommendation, the coverage provisions of the Affordable Care Act now require the inclusion of IBT for obesity without any cost-sharing. The USPSTF recommendation is a promising development as an alternative treatment approach available for physicians and for their obese patients.22

12 Bariatric surgery includes a variety of procedures that change either the size or pathways of the stomach to significantly restrict the amount of food a person can consume, thereby reducing caloric intake.

13 H. Buchwald, Y. Avidor, et al. 2004. Bariatric Surgery: A Systematic Review and Meta-analysis. Journal of the American Medical Association 292(14): 1724–1737. http://jama.jamanetwork.com/article.aspx?articleid=199587 (accessed 10/1/13)

14 L. Sjӧstrӧm, M. Peltonen, et al. 2012. Bariatric Surgery and Long-Term Cardiovascular Events. Journal of the American Medical Association 307(1): 56–65. http://jama.jamanetwork.com/article.aspx?articleid=1103994 (accessed 10/1/13).

15 This requirement might be waived for patients with BMI≥ 50.

16 W. E. Encinosa, D. M. Bernard, C. A. Steiner, and C-C Chen. 2005. Use and Costs of Bariatric Surgery and Prescription Weight-Loss Medications. Health Affairs 24(4): 1039–1046. http://content.healthaffairs.org/content/24/4/1039.full.pdf+html (accessed 11/14/13).

17 N. T. Nguyen, H. Masoomi, C. P. Magno, et al. 2011. Trends in the Use of Bariatric Surgery, 2003–2008. Journal of the American College of Surgeons 213(2): 261–266. http://www.sciencedirect.com/science/article/pii/S1072751511003401 (accessed 10/28/13).

18 Though the data is not shown here, 50 adults in this BCBSM study population underwent bariatric surgery in 2010.

19 The U.S. Preventive Services Task Force defines intensive behavioral therapy for obesity as two or more counseling sessions per month for the first three months of intervention and may include group/ individual sessions, diet counseling, physical activity, and behavior change strategies. The USPSTF does not explicitly define the core components of IBT, but in general states that effective IBT interventions involve multiple behavioral management activities and at least 12 sessions.

20 E.S. LeBlanc, E. O’Connor, et al. October 4, 2011. Effectiveness of Primary Care-Relevant Treatments for Obesity in Adults: A Systematic Evidence Review for the U.S. Preventive Services Task Force. Annals of Internal Medicine 155(7): 434–447.

21 In general, a weight reduction of 5 percent is considered clinically meaningful.

22 Section 2713 of the Patient Protection and Affordable Care Act states that “A group health plan and a health insurance issuer offering group or individual health insurance coverage shall, at a minimum, provide coverage for and shall not impose any cost sharing requirements for— (1) Evidence-based items or services that have in effect a rating of ‘A’ or ‘B’ in the current recommendation of the United States Preventive Services Task Force.” Sections 4105 and 4106 outline the same coverage requirements for Medicare and Medicaid, respectively.


While obesity has a great impact on many lives in Michigan, those who are severely obese have the highest health care costs and are far more likely to have a serious chronic health condition, such as type 2 diabetes. Indeed, those who are moderately obese are closer to those who are overweight both with regard to chronic disease and health care spending. The implications of this finding are significant. First, considerable health problems can be avoided and health care cost reduced if individuals, clinicians, and families can help prevent the progression of moderate obesity to severe obesity. And, second, once an individual is severely obese, it is essential that clinicians encourage the use of evidence-based treatment approaches, specifically, bariatric surgery and /or IBT. Fortunately, data indicate that many severely obese individuals are highly motivated and interested in pursuing effective interventions.

This study shows that more can be done to reduce obesity in Michigan and nationally. By focusing on proven strategies and targeting interventions to fit the circumstances of individuals in need, we can make a difference in both reducing the disease burden faced by individuals along with reducing the attendant health care costs.

Methodology & Definitions

This report linked 2010 health risk assessment (HRA) data with 2010 health care claims data for adults who were continuously enrolled with BCBSM in 2010.

Weight categories were defined by calculating body mass index (BMI), the ratio of weight to height (measured in kg/m2). BMI calculations were based on self-reported height and weight in the HRA data and were grouped according to BMI ranges typically used for such studies: underweight (BMI <18.5 kg/m2); healthy weight (18.5–24.9 kg/m2); overweight (25–29.9 kg/ m2); and obese (30 kg/m2 or greater). The obese category can be further stratified into moderately obese (30–34.9 kg/m2) and severely obese (35 kg/m2 or greater) to provide a more nuanced understanding of differences within the broad category of obesity. Figure 7

Figure 7
Body Mass Index (BMI) Categories, Adults

BMI Category (kg/m2)
Underweight (<18.5)
Healthy Weight (18.5–24.9)
Overweight (25–29.9)
Moderately Obese (30–34.9)
Severely Obese (35+)
  lbs 100 120 140 160 180 200 220 240 260 280 300
kg 45.4 54.4 63.5 72.6 81.6 90.7 99.8 108.9 117.9 127.0 136.1
Ft' In" m  
4' 10" 1.47   20.9 25.1 29.3 33.4 37.6 41.8 46.0 50.2 54.3 58.5 62.7
5' 0" 1.52   19.5 23.4 27.3 31.2 35.2 39.1 43.0 46.9 50.8 54.7 58.6
5' 2" 1.57   18.3 21.9 25.6 29.3 32.9 36.6 40.2 43.9 47.6 51.2 54.9
5' 4" 1.63   17.2 20.6 24.0 27.5 30.9 34.3 37.8 41.2 44.6 48.1 51.5
5' 6" 1.68   16.1 19.4 22.6 25.8 29.1 32.3 35.5 38.7 42.0 45.2 48.4
5' 8" 1.73   15.2 18.2 21.3 24.3 27.4 30.4 33.5 36.5 39.5 42.6 45.6
5' 10" 1.78   14.3 17.2 20.1 23.0 25.8 28.7 31.6 34.4 37.3 40.2 43.0
6' 0" 1.83   13.6 16.3 19.0 21.7 24.4 27.1 29.8 32.5 35.3 38.0 40.7
6' 2" 1.88   12.8 15.4 18.0 20.5 23.1 25.7 28.2 30.8 33.4 35.9 38.5
6' 4" 1.93   12.2 14.6 17.0 19.5 21.9 24.3 26.8 29.2 31.6 34.1 36.5
6' 6" 1.98   11.6 13.9 16.2 18.5 20.8 23.1 25.4 27.7 30.0 32.4 34.7
6' 8" 2.03   11.0 13.2 15.4 17.6 19.8 22.0 24.2 26.4 28.6 30.8 33.0
6' 10" 2.08   10.5 12.5 14.6 16.7 18.8 20.9 23.0 25.1 27.2 29.3 31.4

Individuals who were underweight were excluded from the analyses due to small numbers. Pregnant women were also excluded from the study. After exclusions, data represented HRA responses and health care claims for 29,691 commercially insured adults aged 18 or older who lived in Michigan in 2010. To our knowledge, no other study has applied this same methodology to study obesity in the privately insured population in Michigan.

Data related to weight management were obtained from self-reported HRA responses. Comorbid conditions were defined by ICD-9 diagnosis codes. Health care costs were defined by allowed amounts, which represent health care expenditures paid by both the insurer and the members.


This report analyzed data for adults with BCBSM commercial insurance coverage in 2010, so findings may not be generalizable to broader populations. In addition, body mass indices were calculated based on self-reported height and weight rather than direct measurement, so respondents may have understated or overstated their height or weight, limiting the accuracy of analyses based on BMI categories.


Table A-1
Prevalence of Weight Categories and Associated Total and Average Annual Health Care Costs, by Weight Category, BCBSM, 2010

Weight Category N % of Study Population Total Annual Health Care Costs % of Total Annual Health Care Costs Avg. Annual Health Care Costs per Individual
Healthy Weight 8,485 28.6% $31,579,632 23.5% $3,722
Overweight 10,865 36.6% $43,923,064 32.7% $4,043
Moderately Obese 6,089 20.5% $28,726,203 21.4% $4,718
Severely Obese 4,252 14.3% $30,260,414 22.5% $7,117
Total Study Population 29,691 100% $134,489,313 100% $4,530

Table A-2
Prevalence of Comorbid Conditions, by Condition and Weight Category, BCBSM, 2010

Comorbid Condition Prevalence by Weight Category
Healthy Weight Overweight Moderately Obese Severely Obese
Acid Reflux 8.7% 10.5% 11.5% 14.0%
Asthma 2.7% 2.9% 3.4% 5.2%
Back Pain 7.6% 8.5% 9.5% 11.7%
Cancer 1.3% 1.3% 1.7% 2.0%
Congestive Heart Failure 0.1% 0.3% 0.3% 1.0%
Chronic Obstructive Pulmonary Disease 2.3% 2.2% 3.2% 3.9%
Coronary Artery Disease 1.6% 3.0% 4.2% 4.8%
Depression 5.3% 4.3% 4.8% 6.9%
Type 2 Diabetes 2.5% 5.8% 9.5% 19.0%
Gallbladder Disease 0.5% 0.8% 1.3% 1.4%
Hyperlipidemia 12.9% 20.8% 24.6% 23.9%
Hypertension 7.8% 15.2% 22.7% 29.9%
Osteoarthritis 2.8% 3.9% 5.6% 7.8%
Sleep Apnea 0.2% 0.6% 1.6% 2.7%

Table A-3
Prevalence of Having a 1, 2, or 3+ Comorbid Conditions, by Weight Category, BCBSM, 2010

BMI Category 1 Comorbid Condition 2 Comorbid Conditions 3+ Comorbid Conditions
Healthy Weight 23.0% 8.9% 4.6%
Overweight 25.6% 12.8% 8.3%
Moderately Obese 25.8% 16.8% 12.6%
Severely Obese 25.7% 18.5% 19.0%

Table A-4
Percentage of Individuals Actively Managing Weight and Percentage Confident They Can Improve Weight Management, by Weight Category, BCBSM, 2010

Weight Category Actively trying to manage weight for less than 6 months Actively managing weight for 6 months or more Confident/extremely confident they can improve weight management
Healthy Weight 11.1% 34.8% 1.5%
Overweight 23.8% 26.5% 38.7%
Moderately Obese 35.9% 15.0% 38.2%
Severely Obese 38.6% 11.6% 36.0%

Suggested citation: Hemmings, Brandon and Udow-Phillips, Marianne. Obesity in Michigan: Impact and Opportunity. January 2014. Center for Healthcare Research & Transformation. Ann Arbor, MI.