The effects of caffeine on the human body's breakdown of fats are not extensively known and research continues to be inconclusive.
New research has shown that the administration of caffeine causes an increased concentration of fatty acids in plasma. This study indicates that this action stimulates lipolysis, the breakdown of fats in the body, and results in loss of fat and weight.
However, the conclusion of that study conflicts with the results from other research done on animals that shows that although caffeine intake increases the transformation of fatsinto fatty acids during digestion, and a greater concentration of fatty acids in plasma is observed, increased oxidation of these fatty acids does not occur. Cells do not obtain additional energy from these substances. Therefore, caffeine would not contribute much to weight loss.
The way in which one individual's body breaks down caffeine is not necessarily the same as someone else's (there are some who are more sensitive to it), but it is estimated that around 80% of caffeine is broken down into paraxanthine, and 16% is converted into theobromine and theophylline in the liver. Because it is a water-soluble substance, caffeine and its metabolites are eliminated in the urine, and generally, moderate consumption will not produce adverse effects on the body.
The majority of epidemiological information available indicates that consuming less than 300 mg of caffeine a day (2-3 cups of coffee) doesn't involve any risks; however, pregnant women, people with medical conditions, and those who are sensitive to caffeine should limit their intake or eliminate it from their diet completely.
