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Green tea stackers don't work without exercise

Supplements containing moderate doses of green tea extracts help the body to burn more fat, but don't increase energy expenditure. Research done by green-tea extract manufacturer DSM shows that Ephedra-stackers' successors only work if you exercise as well. And preferably on an empty stomach.

Researchers at Universitary Medicine Berlin and DSM Nutritional Products will soon publish in the European Journal of Clinical Nutrition the results of a study they did on ten overweight men. The men were given supplements for three days. The researchers performed their measurements on day 3 of the trial. During the first five hours of measurements the subjects were given nothing to eat or drink. Then they were given a meal and measurements continued for another four hours.

The researchers took 5 measurements on each person: after the men had been given a placebo, 300 mg EGCG [low EGCG], 600 mg EGCG [high EGCG], 200 mg caffeine or a supplement containing 200 mg caffeine and 300 mg EGCG. The men spread the doses over two intake moments per day. On day three they took the entire daily dose at one go in the morning. They took the capsules one hour before a meal, and washed them down with water.

The supplements did not raise the men's total energy expenditure [EE]. The figure below is for the supplement containing 200 mg caffeine and 300 mg EGCG. The figures for the other supplements are not very different. Black = placebo; white = supplement.

Green tea stackers don't work without exercise

The researchers examined the men first before they had eaten, then gave them a meal after 300 minutes, and four hours later examined them again.

The supplements changed where the body got its energy from. The supplements caused the test subjects to use more fat as a fuel source, and less carbohydrates. This effect would be desirable for athletes, but the test subjects did no exercise.

Green tea stackers don't work without exercise

Green tea stackers don't work without exercise

The meal that the men were given resulted in a downward plummet. The meal consisted of 50 percent energy derived from carbohydrates, 15 percent from protein and the rest from fat.

The increase in fat burning was highest in the men who took 200 mg caffeine + 300 mg EGCG, but even in this group the body's total energy expenditure did not increase.

The results might cause you to speculate that the combination of EGCG and caffeine works better if you follow a low-carb diet. But if you look at the concentration of free fatty acids [NEFA] in the blood, then another idea comes to mind. It's above all the combination of caffeine and the EGCG with caffeine that increases the NEFA concentration. Black = placebo; white = supplement.

Green tea stackers don't work without exercise

"Although within the physiological range, fasting plasma nonesterified fatty acids were significantly higher with 200mg caffeine and the combination of 300mg EGCG/200mg caffeine when compared with 300mg EGCG alone, suggesting that lipid mobilization slightly exceeded the capacity of lipid oxidation when caffeine is consumed either alone or with EGCG", the researchers write.

If the test subjects had exercised as well, the supplements probably would have increased total energy expenditure.

Eur J Clin Nutr. 2010 Apr 7. [Epub ahead of print].

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