From Ergo Log
A supplement containing a blend of EGCG and caffeine increases the amount of energy the body-at-rest expends in a day by an average of 158 kcal. Researchers at the Canadian Laval University discovered this in trials they did with 14 volunteers, each lasting 24 hours. If you extrapolate the results, it means that you could lose a kilogram of fat in 40 days by taking this kind of supplement.
Caffeine blocks the adenosine receptors in the body’s cells and inibits the enzyme phosphodiesterase, and thus raises metabolism. EGCG inhibits the enzyme that breaks down adrenalin and noradrenalin in the body. The compound has a direct effect on cells and also makes the mitochondria work harder.
The research was commissioned by Iovate Health Sciences. The researchers tested combinations of guarana and green tea in their experiments. The extracts were standardised in such a way that the test subjects got 600 mg caffeine [divided over 3 intakes] each day. The amount of EGCG varied. The test subjects – men aged between 20 and 50 with a sedentary lifestyle – were given a daily 270, 600, 900 or 1200 mg of EGCG.
The more EGCG the test subjects got, the more energy they expended during a 24-hour period in a metabolic chamber. This is a room in which researchers can measure to the kilocalorie exactly how much energy a person uses.
The 270 mg group burned an extra 158 kcal in a day compared with the placebo group. The 600 mg group burned 170 kcal more. The 900 mg group used up 188 kcal extra and the 1200 mg group burned an extra 197 kcal. The differences in energy expenditure between the EGCG groups were not statistically significant.
In theory you could lose a kilogram of body fat in 40 days with the lowest dose of EGCG. The highest dose would help you do so in 36 days. In theory.
The supplements led to an increase in diastolic [between two heartbeats] and systolic [during one heartbeat] blood pressure.
German research done in 2005 also showed that a combination of caffeine and EGCG resulted in an extra 180 kcal energy expenditure per day. According to the German study, however, a daily intake of 300 mg EGCG is sufficient. [DSM Nutritional Products 10 Oct 2006]
Br J Nutr. 2005 Sep;94(3):432-6.