Wearing seat belts and driving safely are two ways to protect yourself from dying in a car accident. Losing weight might be another one.
A recent study found that a person's weight appears related to how bad their injuries will be in a car accident.
Underweight people were about 19 percent more likely to die in a car crash than people with a normal, healthy weight.
Obese people were about 21 percent more likely to die, and extremely obese individuals were about 50 to 80 percent more likely to die in a car crash than normal weight people.
The study, led by Thomas R. Rice, PhD, of the Division of Environmental Health Sciences at the University of California at Berkeley, looked at whether being obese had any link to people's injuries in car accidents.
The researchers used the data in the US Fatality Analysis Reporting System for all accidents that were reported between 1996 and 2008. This time period included 57,491 deaths.
The database, run by the National Highway Traffic Safety Administration, includes all deaths that occurred within 30 days of a vehicle accident.
The researchers narrowed the data down to crashes occurring between two similar two-passenger (or more) vehicles in which the crash impact was the primary factor causing injury. Drivers were at least 16 years old.
There were 3,403 crashes in which the researchers had data on the age and weight of the passengers as well as whether they were wearing seat belts and whether the airbags deployed.
The researchers classified drivers by body mass index (BMI), a ratio of a person's height to weight used to categorize someone as being a healthy weight or being overweight or underweight.
Among these drivers, 46 percent were a healthy, normal weight, and a third (33 percent) were overweight. Obese individuals comprised 18 percent of the drivers. One third of the drivers were not wearing seat belts, and the airbags deployed in 53 percent of cases.
Obese individuals (BMI of 30 to 34.9) were about 21 percent more likely to die in a car crash, and severely obese drivers (BMI of 35 to 39.9) were about 51 percent more likely to die than normal weight drivers.
Those who were morbidly obese (BMI at or over 40) were 80 percent more likely to die of their injuries in a car crash than individuals of a healthy weight.
Drivers who were underweight were about 19 percent more likely to die in a car crash than drivers who were a normal, healthy weight.
The researchers did not find any differences in these rates when they looked at differences in the cars' makes or models, the type of collision or the use of a seat belt.
"Findings from this study suggest that obese vehicle drivers are more likely to die from traffic collision-related injuries than non-obese occupants involved in the same collision," the researchers wrote.
"The ability of passenger vehicles to protect overweight or obese occupants may have increasingly important public health implications, given the continuing obesity epidemic in the USA," they added.
The study was published January 21 in the Emergency Medicine Journal. No conflicts of interest were reported.