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

Abstract

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/m 2 ) were fed in energy balance from day 1 to day 3, followed by a LED with GT (1125 mg tea catechins þ225 mg caffeine/d) or placebo (PLAC) from day 4 to day 87. Caffeine intake was standardised 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.

The effect of caffeine, green tea and tyrosine on thermogenesis and energy intake

“…The lack of thermogenic effect of GTE found in the present study supports other studies investigating the effect of catechins on energy expenditure (Kovacs et al, 2004;Diepvens et al, 2005;Klaus et al, 2005). However, most studies examining the effect of tea catechins have found that the agents were able to enhance thermogenesis even at smaller doses than those in present study (Dulloo et al, 1999(Dulloo et al, , 2000Berube-Parent et al, 2005;Westerterp-Plantenga et al, 2005), which suggests that tea catechins possess thermogenic properties.…”

“…However, the significantly greater desire to ingest more fat and sweet foods following GTE supplementation may, in real life, offset the potential gains from a decreased EI. Only few studies have investigated a possible anorectic effect of GTE and the evidence is contradicting in both rodent studies (Kao et al, 2000;Klaus et al, 2005) and human studies (Kovacs et al, 2004;Diepvens et al, 2005;Westerterp-Plantenga et al, 2005).…”

The effects of green tea on weight loss and weight maintenance: a meta-analysis

“…[10][11][12][13][14][15][16][17] On the other hand, studies with Caucasian subjects reported mixed results. [18][19][20] Moreover, the amount of regular caffeine intake may also influence the effectiveness of catechins. In a study from WesterterpPlantenga et al, 20 it was shown that a regular caffeine intake of 4300 mg per day in Caucasian subjects diminished the effects of an EGCG-caffeine mixture on WM, in comparison with subjects that had a regular caffeine intake of o300 mg per day.…”

The Effect of Metabolism-Boosting Beverages on 24-hr Energy Expenditure

“…They also evaluated EGCGcaffeine mixtures plus guarana, and found that all significantly increased 24-hour energy expenditure by 750 kJ (~160 kcal) (8%). Diepvens et al [31] performed a randomized, double-blind, placebo controlled trial to examine the effect of green tea extract, along with a low energy diet, on REE in 46 overweight women. REE, as a function of fat-free mass, was significantly reduced over the 32-day study period in the placebo group, but not the group receiving green tea (1125 mg tea catechins + 225 mg caffeine/day).…”