Research

Mixed

Higher body mass index (BMI) is associated with a dose-response increase in the risk of severe COVID-19 outcomes, including hospitalization, ICU admission, invasive mechanical ventilation, and death, with the lowest risk observed at BMIs near the healthy weight/overweight threshold (23.7–25.9 kg/m²).

Maintaining a BMI in the healthy weight range (18.5–24.9 kg/m²) is associated with the lowest risk of severe COVID-19 outcomes, including hospitalization and death. If you have obesity or are overweight, you are at a higher risk for severe illness, and this risk increases with higher BMI categories. Public health recommendations include prioritizing vaccination, masking, and accessing resources to support a healthy weight through nutrition and physical activity.

GoodSupportsHIGH confidence
Risks for hospitalization, ICU admission, and death were lowest among patients with BMIs of 24.2 kg/m2, 25.9 kg/m2, and 23.7 kg/m2, respectively, and then increased sharply with higher BMIs.
Lyudmyla Kompaniyets et al. · MMWR Morbidity and Mortality Weekly Report · 2021

Why this rating

Large sample size (n=148,494), multi-hospital data, adjusted for multiple covariates, though observational design limits causal inference.

Source

Body Mass Index and Risk for COVID-19–Related Hospitalization, Intensive Care Unit Admission, Invasive Mechanical Ventilation, and Death — United States, March–December 2020

Lyudmyla Kompaniyets et al. · MMWR Morbidity and Mortality Weekly Report · 2021

DOI 10.15585/mmwr.mm7010e4

cohort · n=148494Cited 451×
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DOI resolved against Crossref · corpus check 2026-06-10

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