DEAR DR. BLONZ: I have questions about alcohol. I read that when you take in alcohol, your body halts all fat-burning for 12 to 36 hours. Is this accurate? How long does it take the liver to break down the alcohol in one drink? -- W.T., Tulsa, Oklahoma
DEAR W.T.: Alcohol does affect the body's ability to burn fats, but that duration is off. Ingested alcohol is treated as a toxin by the body, getting broken down (metabolized) on a priority basis by the liver. There are limits to how fast this can take place. While the fat-burning process is ongoing, it is impaired, because the intermediates produced during alcohol's breakdown turn off critical enzymes in the liver that process fats.
A reasonable estimate is that it takes about an hour to break down the alcohol in one drink. A standard drink will contain 0.6 ounces or 14 grams of alcohol, which is the amount in a 12-ounce can of beer (5% alcohol), 5 ounces of wine (12% alcohol) or a 1.5-ounce shot of spirits (80 proof, which is 40% alcohol).
Every gram of alcohol provides seven calories. (For comparison, there are four calories in a gram of protein or carbohydrate, and nine calories in a gram of fat.) So the 14 grams of alcohol in that standard drink provide 98 calories. (Check the calorie count of various drinks at the National Institutes of Health, b.link/b6gbaj.) It is important to note that you can't accelerate the burning of these calories by exercising, as muscles cannot use alcohol's calories that way.
The liver gets to work soon after the first swallow. While each gram waits its turn, the alcohol and its metabolites distribute in bodily fluids; this includes blood and tissue water (muscles, for example, are about 80% water by weight). When consumed faster than the liver can handle it, which tends to be the case, the concentration in the blood rises, and we begin to experience intoxication and alcohol's other effects.
The larger you are, the more alcohol you may seem to "tolerate" -- not because you break alcohol down any faster, but because you have a larger amount of body water for that dilution. Another factor is body composition: Those with a higher lean body mass (that is, a lower percentage of body fat) will also have more body water to dilute the alcohol and its metabolites.
Every gram of alcohol needs to be metabolized. Keeping in mind that hour-per-drink formula, if two similar people, differing only in body size, drink the same amount of alcohol, the smaller person will experience the more significant effect. If they drink to produce the same blood alcohol concentration, the smaller individual will have consumed less alcohol, so they might sober up faster.
Back to fats: Alcohol does inhibit the normal breakdown and processing of fats by the liver. Alcohol also facilitates the production of triglycerides, but leaves the liver with a limited way to export them for storage; this helps explain why chronic heavy drinking is associated with the development of fatty liver disease.
What hangs on the longest? Certain alcohol metabolites. These can be detected in the blood well after any buzz is gone, but that does not mean that fat-burning has remained halted during this extended period. For more on alcohol, see b.link/qvbn8h, information on fatty liver disease is at b.link/uqrja9.
Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.