Individuals differ in their alcohol processing rates. Which physiological factor mainly contributes to this difference?

The physiological factor that mainly contributes to differences in alcohol processing rates is the composition of fat versus muscle tissue. Alcohol is distributed in body water, and since muscle tissue contains more water than fat tissue, individuals with a higher muscle-to-fat ratio generally have a lower blood alcohol concentration (BAC) after consuming the same amount of alcohol compared to those with a higher proportion of body fat. This difference in body composition impacts how alcohol is metabolized and eliminated from the body.

Understanding the role of body composition is essential because it highlights why two individuals of the same weight may experience different levels of intoxication after drinking. For example, a person with more muscle mass might process alcohol more efficiently and experience less impairment than someone with a higher fat ratio. This factor is crucial in assessing one's ability to safely operate a vehicle after consuming alcohol.