The scientists fed laboratory rats on a high fat diet chow with either 0%, 1.1% or 2.2% of green tea extract [GTAE] added and found that only the chow containing 2.0% GTAE had significant effects on body weight gain (5.6% less than control) and visceral fat accumulation (-17.8% vs. control). Yet, they observed a
[...] considerably (P < .05), reduction in the digestion of protein (but not fat) was observed in both GTAE groups (1.1% GTAE: 82.6% ± 1.8%; 2.0% GTAE: 84.3% ± 0.8%) when compared to the control (93.3% ± 1.5%).This novel finding appears to stand in line with previous studies, in which green tea supplementation decreased fat absorption in the intestine. Interestingly, this effect was absent / non-significant in the current study (cf. figure 1).
|Figure 1: Daily food intake, FER, apparent digestion of protein and fat, energy value of feces, and visceral fat content of treatment and control groups (Bajerska. 2011)|
It is also noteworthy that, in view of the dose-response relationship between the amount of extract the rats consumed and its effect on their body weight, these results do also indicate that the amounts of GTAE you usually find in so-called "fat burners" will hardly have any direct effect on your body weight or fat, no matter what the respective supplement companies are telling you.