I was reading Duff McKagan’s biography where he talked about drinking up to a gallon of vodka a day.
Since a gallon of vodka has about 8,000 calories in it, I was confused how that is possible without gaining 2 lbs a day and ending up super morbidly obese pretty quickly. I’ve heard other stories of heavy alcoholics drinking half a gallon a day of hard liquor which on paper should lead to massive weight gain, but usually doesn’t.
Anyway, researching it I found there are at least 3 metabolic pathways for ethanol metabolism.
The ADH pathway, MEOS/CYP2E1 and catalase.
So apparently, alcohol metabolized through the ADH pathway provides 7 calories per gram of ethanol, but alcohol metabolized through the MEOS pathway also provides 7 calories, but the energy required to use this pathway burns 9 calories per gram. The conversion of NADPH to NADP+ and the excess heat given off burn more calories than the ethanol provides.
Which begs the question, which pathway does the body use in what situations? A fifth of vodka could have 1656 calories, or it could have -473. I can’t find anything about the third pathway, or how common it is, or how much energy that extracts from ethanol.
Reading online, one person implied in low doses alcohol is treated like food and processed via the ADH pathway, but in high doses it is treated like a drug and processed via the MEOS pathway. But other sources imply that the MEOS pathway is only used in chronic alcoholics and even if BAC is high in a person who drinks seldomly, it’ll still be processed via the ADH pathway.
So does anyone know? For the following situations
- Person drinks 2 glasses of wine every day after dinner
- Person drinks 1-2x a week until their BAC is 0.1
- Person drinks 1-2x a week until their BAC is 0.25
Does all of that get processed via the ADH system? Is the MEOS system only used by chronic alcoholics?