In the United States, 41.9 % of adults are obese, and 9.2 % are severely obese, according to the Centers for Disease Control and Prevention (CDC) [[1], [2], [3]]. Obesity is a risk factor for multiple comorbidities, such as hypertension, diabetes mellitus, renal dysfunction, and several malignancies [[3], [4], [5], [6], [7], [8]]. The “Obesity Paradox” is a phenomenon in which increasing body mass index (BMI) has a theorized protective effect on mortality in several disease states, such as diabetes mellitus, coronary artery disease, certain malignancies, and the critically ill [[3], [4], [5], [6],[9], [10], [11]].

In trauma patients, the obesity paradox theorizes a survival benefit secondary to the cushioning effect of adiposity [8,12,13]. Several studies demonstrate increased mortality associated with increasing BMI [3,[14], [15], [16]]. Alternatively, multiple studies report no difference in mortality based on BMI in the trauma population [7,8,12,17]. Further, some studies reported that increased BMI potentially protects against mortality [18,19].

Trauma remains the leading cause of death under the age of forty-five years in the United States [20]. Blunt trauma accounts for 80 to 90 % of all traumatic injuries in the United States, with abdominal injuries occurring in 6 to 15 % of patients [[21], [22], [23]]. Given the significant prevalence of obesity and traumatic injury in the United States, it is essential to understand the nuances in morbidity and mortality outcomes in the obese trauma population.

We aim to evaluate the impact of BMI on abdominal injury severity, morbidity, and mortality in adults with isolated, blunt abdominal trauma in the United States.