Oolong & the weight loss connection
The two main ways to reduce food related body weight are; increase energy expenditure (EE) and inhibit the absorption of nutrients, including fat and carbohydrates. Caffeine is a stimulant so it is widely accepted that the caffeine in tea increases metabolism, hence increasing EE. So the question becomes, is it only the caffeine or are other compounds in the tea contributing to that increase?
The Research
The Chinese have long believed that Oolong tea is beneficial in reducing and maintaining weight. A Chinese study, in 1998, of 102 females showed that continuous consumption of Oolong tea for 6 weeks resulted in a reduction of body weight. This study, along with the question of other compounds contributing to tea’s weight loss benefits, spurred further research.
In 2001, Physiologist Dr. William Rumpler, of the US Agriculture Research Services’ Diet and Human Laboratory, investigated the ancient Chinese belief that Oolong tea is effective in controlling body weight. The study measured how tea influences energy expenditure (EE) and included 12 male volunteers who were given 4 separate beverage formulas over three consecutive days. The beverage formulas consisted of; 1) full strength Oolong tea, 2) caffeinated water with caffeine equal to full strength Oolong tea, 3) half strength Oolong tea and 4) non caffeinated water
The participants 24 hour EE was measured and resulted in;
| • | EE levels of about 3% higher when they drank either the full strength Oolong tea or the caffeinated water versus the non caffeinated water. |
| • | Participants burned an average of 67 more calories per day when drinking
the full strength Oolong tea. |
| • | Participants increased fat oxidation (fat burning) by a whooping 12% after consuming the full strength Oolong tea versus the caffeinated water. |
| • | This data confirms that a component other than caffeine is responsible for promoting the preferential use of fat as an energy source.
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The increase in fat oxidation in this study is amazing! Drinking Oolong tea can actually tell your body to burn fat for energy! Scientists then speculated that caffeine combined with EGCGs worked together to increase fat oxidation.
A Japanese study, conducted in 2003, went one step further comparing the benefits of Oolong tea and green tea on weight reduction. 11 healthy young female students participated in this well controlled study. Participants received three different beverage formulas; 1) Oolong tea, 2) powdered green tea leaves and 3) water
Both teas were prepared with boiling water. The Oolong tea steeped for 5 minutes and the powdered green tea leaves were dissolved.
After measurements were taken, the results determined;
| • | Oolong tea had higher EE levels from beginning to end and at intervals of 30, 60, 90 and 120 minutes. | ||
| • | EE levels peaked at 90 minutes for both Oolong and green tea and remained at their respective levels until 120 minutes. | ||
| • | These results indicate that after consuming Oolong tea you will expend more energy then if you were to drink green tea or water and that it can last up to two hours. | ||
The concentrations of caffeine, individual catechins and other polyphenols were also measured producing these interesting findings;
| • | The caffeine and EGCG content was much higher in the green tea vs. the Oolong tea. |
| • | The concentration of polymerized polyphenols was significantly higher in the Oolong tea versus the green tea. |
These findings show that it’s the polymerized polyphenols, highest in Oolong tea, that link tea to burning fat, not just the caffeine or just the combination of caffeine and EGCGs.
Furthermore, the rest of the compounds compared in the teas were similar or equal to one another with no marked differences, reinforcing the results.
We have shown that Oolong tea significantly increases EE for up to as much as 120 minutes and can even promote preferential use of fat as an energy source making it a healthy tool for reducing and maintaining weight. So what about absorption of nutrients?
Oolong tea’s effect on blocking the absorption of fats and carbohydrates is thought to play a key role in its weight reducing benefits. While more studies need to be done, initial studies indicate that Oolong tea has absorption blocking potential.
There are proven methods for losing weight and keeping it off; exercise, getting enough sleep and eating a balanced diet. Oolong tea can enhance these positive changes and garner faster results.