Association of body mass index with health care expenditures in the U.S. by age and sex

A CHOICES study shows that excess body weight is associated with higher health care costs for people across a wide range of body-mass-index (BMI) levels in the U.S.

Association of body mass index with health care expenditures in the United States by age and sex
Ward ZJ, Bleich SN, Long MW, Gortmaker SL. PLOS ONE. 2021 Mar;16(3): e0247307. doi10.1371/journal.pone.0247307.
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Estimated Age-Specific Medical Expenditures by BMI Category

Estimated Age-Specific Medical Expenditures by BMI Category
[CREDIT: Ward et al, 2021, PLOS ONE (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)]
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Abstract

Background
Estimates of health care costs associated with excess weight are needed to inform the development of cost-effective obesity prevention efforts. However, commonly used cost estimates are not sensitive to changes in weight across the entire body mass index (BMI) distribution as they are often based on discrete BMI categories.

Methods
We estimated continuous BMI-related health care expenditures using data from the Medical Expenditure Panel Survey (MEPS) 2011–2016 for 175,726 respondents. We adjusted BMI for self-report bias using data from the National Health and Nutrition Examination Survey (NHANES) 2011–2016, and controlled for potential confounding between BMI and medical expenditures using a two-part model. Costs are reported in $US 2019.

Results
We found a J-shaped curve of medical expenditures by BMI, with higher costs for females and the lowest expenditures occurring at a BMI of 20.5 for adult females and 23.5 for adult males. Over 30 units of BMI, each one-unit BMI increase was associated with an additional cost of $253 (95% CI $167-$347) per person. Among adults, obesity was associated with $1,861 (95% CI $1,656-$2,053) excess annual medical costs per person, accounting for $172.74 billion (95% CI $153.70-$190.61) of annual expenditures. Severe obesity was associated with excess costs of $3,097 (95% CI $2,777-$3,413) per adult. Among children, obesity was associated with $116 (95% CI $14-$201) excess costs per person and $1.32 billion (95% CI $0.16-$2.29) of medical spending, with severe obesity associated with $310 (95% CI $124-$474) excess costs per child.

Conclusions
Higher health care costs are associated with excess body weight across a broad range of ages and BMI levels, and are especially high for people with severe obesity. These findings highlight the importance of promoting a healthy weight for the entire population while also targeting efforts to prevent extreme weight gain over the life course.