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I generally try not to get too excited about mouse studies, because there’s so much uncertainty about how the results will translate to humans. Still, I was very interested in a new study on fat-burning from Australian researchers at the Garvan Institute of Medical Research. I’ve always been skeptical about the various ways people suggest trying to convince your body to burn fat rather than carbohydrates, whether it’s by keeping your heart rate in a certain zone (usually by going slower than you would otherwise go, which seems silly to me) or by taking some sort of pill.
Anyway, there’s a very good press release describing the new study and providing context, but allow me to quote the key section:
Sydney scientists have demonstrated that mice genetically altered to burn fats in preference to carbohydrates, will convert the unburned carbohydrates into stored fat anyway, and their ultimate weight and body composition will be the same as normal mice.
The research related to an enzyme called ACC2 (acetyl-CoA carboxylase) that controls whether cells burn fats or carbohydrates. There’s no doubt that this is still a very complicated area of research, so I’m certainly not claiming this is the “last word” on this topic. But it reinforces my impression that our primary focus should be on burning (or avoiding) calories, not burning fat.