Methods for Estimating Expected Blood Alcohol Concentration [1980-09]

NHTSA - Behavioral Safety Researchhttps://doi.org/10.21949/15250451980PDFResearch PaperBurns, MarcellineMoskowitz, Herbert, 1925-Southern California Research InstituteUnited States. Department of Transportation. National Highway Traffic Safety AdministrationUnited States. Department of Transportation. National Highway Traffic Safety AdministrationUnited StatesBlood alcohol levelsPhysiological aspectsAccuracyImpaired driving, AlcoholDOT-HS-805-563NTIS-PB81114761DOT-HS-8-01999Final reportEstimates of blood alcohol concentration (BAC) typically are based on the amount of alcohol consumed per pound bodyweight. This method fails to consider either food intake or body composition, factors which significantly affect BAC. A laboratory experiment was conducted to examine amount and type of food and time of food intake in relation to alcohol intake and BAC. Protein and carbohydrates were more effective than fatty foods in reducing the BAC, expected in a fasted state. A moderate to large amount of food, such as a typical full meal, was more effective than lesser amounts, but even a small amount of food had some effect. Time intervals of 1/2 to 4 hours between eating and drinking were investigated; the 1/2 hour interval was most effective in an inverse relationship. At 4 hours there was no food effect. In a study of body conposition and BAC, 20 men and 20 women were subjects. Estimates of percent body fat were caculated using body circumferences or skinfold measurements. Subjects were dosed with .68 g alcohol/kg bodyweight, and the relationship of BAC to body fat estimate was analyzed. Use of body fat estimates did not increase the accuracy of BAC estimates sufficiently to recommend the method. It may be useful for scientific purposes but appears not to be feasible for widespread use. The data suggest that compared to men, women will achieve the same BAC with 15 percent less alcohol, based on ounces of alcohol per pound bodyweight. Similarly, the overweight person will achieve the same BAC as the average weight person with 10 percent less alcohol. These recommendations reflect the male-female differences in body composition, and the higher percent body fat in the obese body. /Abstract from report summary page/129