Caffeine stimulates insuline, as we have been told here. At the same time, caffeine is a fat burner, as we know from other sources. This sounds like a contraddiction. Any comments? Can somebody explain how caffeine manages to burn fat while increasing your insulin levels? Thanks. Paola

Hi Paola, The fat-burning benefits from caffeine come from its ability to inhibit the degradation of cyclicAMP. However, the breakdown of caffiene (as opposed to ingestion) tends to raise insulin levels. As Dr. Sears has said, It's like 1 step forward, two steps back. When I drink caffeine, I find that when I stop, my endurance performance has suffered (but only temporarily as my body adapts). At the same time, I find that I get hungrier more when I am taking in caffiene--thus I have experienced this apparent contradiction.

Thank you Scott. I drink not often coffee (espresso), only two or three times a week, but when I drink one before an endurance event I seem to perform better. I thought this was only a placebo effect at first... Thanks again for your reply. Paola

Hi Paola, <I drink not often coffee (espresso), only two or three times a week, but when I drink one before an endurance event I seem to perform better. I thought this was only a placebo effect at first..>. My experience is also That I perform better after a coffee in an endurance event. I tried plenty of times and my results were consistent. On that basis I have 1 coffee each day (Which is acceptable in the zone) Caffene certainly helps metabolize fat as you say. The effect on insulin varies with individuals. IMO it is wrong to condem something simply because it raises insulin. Eating a zone snack raises insulin. The important point is to control insulin. Sometimes we must do things that raise insulin to the correct level, A morning coffee may certainly work for some people Paola[/quote] White Light

<< The effect on insulin varies with individuals. IMO it is wrong to condem something simply because it raises insulin.>> I hope I wasn't giving the impression that I was condemning any food--just explaining the hormonal consequences. <<Eating a zone snack raises insulin.>> There is a differece between ingesting food that stimulates insulin (and in the case of a Zone snack also stimulates glucagon) and the insulin effects on the breakdown of caffeine. Caffeine apparently decreases insulin sensitivity--which means higher levels of insulin would be required to keep blood glucose levels normal. I am not suggesting that one needs to give up a morning cup of coffee--since as you point out, responses can vary, and other ways of controlling insulin can offset any pontential decrease in sensitivity (ie exercise, more favorable carbs) --just clarifying that the insulin effects of caffeine vs. food are different (stimulation via ingestion vs. decreased sensitivity) Some studies of interest: Keijzers, Gerben B., et al "Caffeine can decrease insulin sensitivity in humans" Diabetes Care 25:364-369, 2002 Biaggioni, Italo, et al "Caffeine: A cause of insulin resistance?" Diabetes Care:399-400,2002 Thong, FS "Caffeine-induced impairment of insulin action but not insulin signaling in human skeletal muscle is reduced by exercise" Diabetes 2002 Mar;51(3):583-90