1) A study of thermogenic effects of commercially available plant preparations done at the Institute of Physiology at
    a Swiss University showed an increase in energy wastage and increased lipolysis as a result of taking Yerba Mate.
    The study also showed that Yerba Mate resulted in "a significant decrease in RQ indicating an enhancement in the
    proportion of fat oxidized, a favorable effect for decreasing body fat."         

    Phytomedicine, Vol. 6(4) pp. 231-238

2) Green tea, by containing high quantities of pharmacologically active compounds can exert a thermogenic and
    therefore an anti-obesity action. Green Tea showed reduced gastric and intestinal fat digestion as well as a reduction
    of the lipid emulsification process. Green Tea was shown to be an effective stimulant for tissue thermogenesis. In a
    study of 10 healthy men, treatment with green tea extract resulted in a significant increase in 24h energy expenditure
    and a significant decrease in 24h respiratory quotient. Administration of green tea extract stimulated thermogenesis
    and fat oxidation and this extract has the potential to influence body weight and body composition via changes in both
    energy expenditure and substrate utilization.