Effect of green tea on resting energy expenditure and substrate oxidation during weight loss in overweight females.

The We assessed the effect of ingestion of green tea (GT) extract along with a low-energy diet (LED) on resting energy expenditure (REE), substrate oxidation and body weight as GT has been shown to increase energy expenditure and fat oxidation in the short term in both animals and people. Forty-six overweight women (BMI 27.6 (sd 1.8) kg/m2) were fed in energy balance from day 1 to day 3, followed by a LED with GT (1125 mg tea catechins +225 mg caffeine/d) or placebo (PLAC) from day 4 to day 87.
Caffeine intake was standardized to 300 mg/d. Energy expenditure was measured on days 4 and 32. Reductions in weight (4.19 (sd 2.0) kg PLAC, 4.21 (sd 2.7) kg GT), BMI, waist: hip ratio, fat mass and fat-free mass were not statistically different between treatments. REE as a function of fat-free mass and fat mass was significantly reduced over 32 d in the PLAC group (P<0.05) but not in the GT group. Dietary restraint increased over time (P<0.001) in both groups, whereas disinhibition and general hunger decreased (P<0.05). The GT group became more hungry over time and less thirsty, and showed increased prospective food consumption compared with PLAC (P<0.05). Taken together, the ingestion of GT along with a LED had no additional benefit for any measures of body weight or body composition. Although the decrease in REE as a function of fat-free mass and fat mass was not significant with GT treatment, whereas it was with PLAC treatment, no significant effect of treatment over time was seen, suggesting that a robust limitation of REE reduction during a LED was not achieved by GT.

British Journal of Nutrition. 94: 1026-1034

Diepvens K., Kovacs E., Nijs I., Vogels N., Westerterp-Plantenga M. (2005)

White Tea, What It Is

White tea is the uncured and unfermented tea leaf. Like black tea, green tea and oolong tea, white tea comes from the camellia sinensis plant. White tea is rapid-dried, while green tea is roasted in a pan or oven (while being stirred for even curing). Black and oolong teas are fermented well before curing.

Loose Leaf White Tea

White teas usually contain buds and younger tea leaves, which have been found to contain lower levels of caffeine than the older leaves, suggesting that the caffeine content of some white teas is lower than that of green teas.

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How Much Caffeine Is In Tea

Caffeine, a naturally occurring chemical that is found in tea, chocolate, coffee beans just to name a few. The amount of caffeine in tea when compared to other drinks is far less than you would think, containing far less then coffee.

Decaffeinated tea (aka DeCaf) is not caffeine free, but caffeine reduced.
Keep in mind herbals are not actually tea as they are mostly made from flowers or other herbs that are caffeine free.