I just found out about an interesting study. It was conducted in Milwakee, USA and it showed that if the person that was involved in a car crash is obese there are more chances that he/she will not make it. A well known fact has been proven some time ago: obesity decreses the body's ability to recover after any kind of injury. Here is what the specialists said:
"Obesity imparts anatomical and physiological changes that may either protect or interfere with the body's response to injury. However, it would be a very costly process to have a car modelled on the person's shape to make it as safe as possible - that's really a bespoke car and would take a lot of money and effort to produce. It would be preferable to try to stop people having car accidents in the first place. People who are obese probably have an adverse risk profile and as such are less able to withstand adverse effects on the body and serious injury."