I was reading Alcohol Revisited on Low Carb by Dana Carpender and something she said jumped out at me:
No doubt, however, that alcohol can be fattening, not only because of the calories it contains, but because it slows metabolism - to quote a medical journal article I read, "Alcohol profoundly inhibits lipolysis." In English this means that alcohol slows fat-burning to a crawl. Like carbs, your body burns alcohol preferentially. Don't expect to burn any fat until you've burned through all your alcohol calories.
First of all, Carpender makes the all-to-common mistake of equating lipolysis with actual fat-burning. As I summarized in Lip-ocabulary , lipolysis is the breaking apart of triglycerides to glycerol and free fatty acids. This occurs constantly in our bodies, inside the fat cells by hormone sensitive lipase (HSL) to release FFA's continually as part of the triglyceride/free fatty acid cycle, and in the capillary beds by lipoprotein lipase (LPL). To further complicate the matter, lipolysis is not stimulated systemically in the same manner. LPL can be activated in fat tissue so as to release FFA's temporarily so that they can be taken up into the adipose tissue, while it is reduced in muscles that don't need the fuel at the moment. In any case, we continually recycle up to 60% of FFA back into triglycerides (storage form) both in fat cells and peripheral tissues. Bottom line, lipolysis rates are not necessarily predictive of ß-oxidation - e.g. "fat burning".
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