Effects of green tea on weight maintenance after body-weight loss. Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial. Green tea catechin plus caffeine supplementation to a high-protein diet has no additional effect on body weight maintenance after weight loss. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Green tea improves metabolic biomarkers, not weight or body composition: a pilot study in overweight breast cancer survivors. Effect of green tea on resting energy expenditure and substrate oxidation during weight loss in overweight females. Effect of green tea extract on obese women: a randomized, double-blind, placebo-controlled clinical trial. Green tea catechin consumption enhances exercise-induced abdominal fat loss in overweight and obese adults. Effects of catechin enriched green tea on body composition.
The present study was conducted to investigate whether green tea may improve weight maintenance by preventing or limiting weight regain after weight loss of 5 to 10 % in overweight and moderately obese subjects. The study had a randomised, parallel, placebo-controlled design. A total of 104 overweight and moderately obese male and female subjects (age 18-60 years; BMI 25-35 kg/m(2)) participated. The study consisted of a very-low-energy diet intervention (VLED; 2.1 MJ/d) of 4 weeks followed by a weight-maintenance period of 13 weeks in which the subjects received green tea or placebo. The green tea contained caffeine (104 mg/d) and catechins (573 mg/d, of which 323 mg was epigallocatechin gallate). Subjects lost 6.4 (sd 1.9) kg or 7.5 (sd 2.2) % of their original body weight during the VLED (P<0.001). Body-weight regain was not significantly different between the green tea and the placebo group (30.5 (sd 61.8) % and 19.7 (sd 56.9) %, respectively). In the green tea treatment, habitual high caffeine consumption was associated with a higher weight regain compared with habitual low caffeine consumption (39 (sd 17) and 16 (sd 11) %, respectively; P<0.05). We conclude that weight maintenance after 7.5 % body-weight loss was not affected by green tea treatment and that habitual caffeine consumption affected weight maintenance in the green tea treatment. This study was undertaken to investigate the effects of green tea on weight reduction in obese Thais. A randomized, controlled trial involving 60 obese subjects (body mass index, BMI > 25 kg/m2) was conducted. All subjects consumed a Thai diet containing 3 meals (8373.6 kJ/day) for 12 weeks, prepared by the Nutritional Unit at Srinagarind Hospital. The diet contained 65% carbohydrates, 15% protein, and 20% fat. Body weight, BMI, body composition, resting energy expenditure, and substrate oxidation were measured at baseline, and during weeks 4, 8, and 12 of the study. Serum levels of leptin and urine VMA were measured at baseline and during the 12th week. Differences over time and between the treatments (green tea or placebo) over time were determined using two-factor ANOVA with repeated measures. In comparing the two groups, differences in weight loss were 2.70, 5.10, and 3.3 kg during the 4th, 8th, and 12th weeks of the study, respectively. At the 8th and 12th weeks of the study, body weight loss was significantly different (P < 0.05). At the 8th week, the difference in resting energy expenditure was 183.38 kJ/day (P < 0.001), the difference in the respiratory quotient was 0.02 (P < 0.05), and no significant differences existed in satiety score, food intake, or physical activity. Urine VMA was significantly different in the 12th week of the study (P < 0.05). We conclude that green tea can reduce body weight in obese Thai subjects by increasing energy expenditure and fat oxidation. Green tea (epigallocatechin gallate + caffeine) and protein each were shown to improve body weight maintenance after weight loss.
                We investigated the effect of a green tea-caffeine mixture added to a high-protein (HP) diet on weight maintenance (WM) after body weight loss in moderately obese subjects.
                A randomized, placebo-controlled, double-blind parallel trial was conducted in 80 overweight and moderately obese subjects [age (mean +/- SD): 44 +/- 2 y; body mass index (BMI; in kg/m(2)): 29.6 +/- 2.0] matched for sex, age, BMI, height, body mass, and with a habitually low caffeine intake. A very-low-energy diet intervention during 4 wk was followed by 3 mo of WM; during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine/d) or placebo, both in addition to an adequate protein (AP) diet (50-60 g protein/d) or an HP diet (100-120 g protein/d).
                Subjects lost 7.0 +/- 1.6 kg, or 8.2 +/- 2.0%, body weight (P < 0.001). During the WM phase, WM, resting energy expenditure, and fat-free mass (FFM) increased relatively in both the HP groups and in the AP + green tea-caffeine mixture group (P < 0.05), whereas respiratory quotient and body fat mass decreased, all compared with the AP + placebo group. Satiety increased only in both HP groups (P < 0.05). The green tea-caffeine mixture was only effective with the AP diet.
                The green tea-caffeine mixture, as well as the HP diet, improved WM independently through thermogenesis, fat oxidation, sparing FFM, and, for the HP diet, satiety; a possible synergistic effect failed to appear. Investigation of the effect of a green tea-caffeine mixture on weight maintenance after body weight loss in moderately obese subjects in relation to habitual caffeine intake.
                A randomized placebo-controlled double blind parallel trial in 76 overweight and moderately obese subjects, (BMI, 27.5 +/- 2.7 kg/m2) matched for sex, age, BMI, height, body mass, and habitual caffeine intake was conducted. A very low energy diet intervention during 4 weeks was followed by 3 months of weight maintenance (WM); during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine per day) or placebo.
                Subjects lost 5.9 +/-1.8 (SD) kg (7.0 +/- 2.1%) of body weight (p < 0.001). At baseline, satiety was positively, and in women, leptin was inversely, related to subjects' habitual caffeine consumption (p < 0.01). High caffeine consumers reduced weight, fat mass, and waist circumference more than low caffeine consumers; resting energy expenditure was reduced less and respiratory quotient was reduced more during weight loss (p < 0.01). In the low caffeine consumers, during WM, green tea still reduced body weight, waist, respiratory quotient and body fat, whereas resting energy expenditure was increased compared with a restoration of these variables with placebo (p < 0.01). In the high caffeine consumers, no effects of the green tea-caffeine mixture were observed during WM.
                High caffeine intake was associated with weight loss through thermogenesis and fat oxidation and with suppressed leptin in women. In habitual low caffeine consumers, the green tea-caffeine mixture improved WM, partly through thermogenesis and fat oxidation. Overweight status after breast cancer treatment may increase a woman's risk for recurrent disease and/or early onset cardiovascular disease. Green tea has been proposed to promote weight loss and favourably modify glucose, insulin and blood lipids. This pilot study tested the effect of daily decaffeinated green tea consumption for 6 months on weight and body composition, select metabolic parameters and lipid profiles in overweight breast cancer survivors.
                The effect of daily decaffeinated green tea intake on weight, body composition and changes in resting metabolic rate, energy intake, glucose, insulin, homeostasis model assessment--insulin resistance (HOMA-IR) and lipids was evaluated in overweight breast cancer survivors. Participants had a mean weight of 80.2 kg; body mass index (BMI) 30.1 kg m⁻²; and body fat 46.4%. Participants (n = 54) were randomised to 960 mL of decaffeinated green or placebo tea daily for 6 months.
                Mean (SD) tea intake among study completers (n = 39) was 5952 (1176) mL week⁻¹ and was associated with a significant reduction in energy intake (P = 0.02). Change in body weight of -1.2 kg (green tea) versus +0.2 kg (placebo) suggests a weight change effect, although this was not statistically significant. Decaffeinated green tea intake was associated with elevated high-density lipoprotein (HDL) levels (P = 0.003) and nonsignificant improvements in the HDL/LDL ratio and HOMA-IR (-1.1 ± 5.9: green tea; +3.2 ± 7.2: herbal).
                Intake of decaffeinated green tea for 6 months was associated with a slight reduction in body weight and improved HDL and glucose homeostasis in overweight breast cancer survivors.
                © 2010 The Authors. Journal compilation © 2010 The British Dietetic Association Ltd. 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 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. To examine the effect of green tea extract (GTE) on obese women and to explore the relationship between GTE and obesity-related hormone peptides.
                A randomized, double-blind, placebo-controlled clinical trial was conducted from July 2006 to June 2007 in Taipei Hospital, Taiwan. Seventy-eight of 100 obese women aged between 16 and 60 years with BMI>27 kg/m(2) and who had not received any other weight control maneuvers within the last 3 months completed this study. The subjects were randomly divided into Groups A and B. Group A (n=41) received GTE while Group B (n=37) took cellulose as a placebo, one capsule (400mg) three times each day for 12 weeks. The body weight (BW), body mass index (BMI) and waist circumflex (WC) were measured at the beginning of the study and after 12 weeks of treatment with GTE. The data were compared and expressed as % reduction.
                There was only a 0.3% reduction in BW (0.15 kg) after 12 weeks of treatment with GTE. There was no statistical difference in % reduction in BW, BMI and WC between the GTE and placebo groups. Within group comparison revealed that the GTE group had significant reduction in LDL-cholesterol and triglyceride, and marked increase in the level of HDL-cholesterol, adiponectin and ghrelin. On the other hand, the placebo group showed significant reduction in triglyceride only, and a marked increase in the level of ghrelin alone.
                This study showed no statistical difference in % reduction in BW, BMI and WC between the GTE and placebo groups after 12 weeks of treatment. The intake of GTE (491 mg catechins containing 302 mg EGCG) for 12 weeks is considered safe as shown by the results. This study evaluated the influence of a green tea catechin beverage on body composition and fat distribution in overweight and obese adults during exercise-induced weight loss. Participants (n = 132 with 107 completers) were randomly assigned to receive a beverage containing approximately 625 mg of catechins with 39 mg caffeine or a control beverage (39 mg caffeine, no catechins) for 12 wk. Participants were asked to maintain constant energy intake and engage in >or=180 min/wk moderate intensity exercise, including >or=3 supervised sessions per week. Body composition (dual X-ray absorptiometry), abdominal fat areas (computed tomography), and clinical laboratory tests were measured at baseline and wk 12. There was a trend (P = 0.079) toward greater loss of body weight in the catechin group compared with the control group; least squares mean (95% CI) changes, adjusted for baseline value, age, and sex, were -2.2 (-3.1, -1.3) and -1.0 (-1.9, -0.1) kg, respectively. Percentage changes in fat mass did not differ between the catechin [5.2 (-7.0, -3.4)] and control groups [-3.5 (-5.4, 1.6)] (P = 0.208). However, percentage changes in total abdominal fat area [-7.7 (-11.7, -3.8) vs. -0.3 (-4.4, 3.9); P = 0.013], subcutaneous abdominal fat area [-6.2 (-10.2, -2.2) vs. 0.8 (-3.3, 4.9); P = 0.019], and fasting serum triglycerides (TG) [-11.2 (-18.8, -3.6) vs. 1.9 (-5.9, 9.7); P = 0.023] were greater in the catechin group. These findings suggest that green tea catechin consumption enhances exercise-induced changes in abdominal fat and serum TG. Obesity is a major health problem in the developed and developing world. Many "functional" foods and ingredients are advocated for their effects on body composition but few have consistent scientific support for their efficacy. However, an increasing amount of mechanistic and clinical evidence is building for green tea (GT). This experiment was therefore undertaken to study the effects of a high-catechin GT on body composition in a moderately overweight Chinese population. In a randomized placebo-controlled trial, 182 moderately overweight Chinese subjects, consumed either two servings of a control drink (C; 30 mg catechins, 10 mg caffeine/day), one serving of the control drink and one serving of an extra high-catechin GT1 (458 mg catechins, 104 mg caffeine/day), two servings of a high-catechin GT2 (468 mg catechins, 126 mg caffeine/day) or two servings of the extra high-catechin GT3 (886 mg catechins, 198 mg caffeine/day) for 90 days. Data were collected at 0, 30, 60, and 90 days. We observed a decrease in estimated intra-abdominal fat (IAF) area of 5.6 cm(2) in the GT3 group. In addition, we found decreases of 1.9 cm in waist circumference and 1.2 kg body weight in the GT3 group vs. C (P < 0.05). We also observed reductions in total body fat (GT2, 0.7 kg, P < 0.05) and body fat % (GT1, 0.6%, P < 0.05). We conclude that consumption of two servings of an extra high-catechin GT leads to improvements in body composition and reduces abdominal fatness in moderately overweight Chinese subjects.
Green tea preparations appear to induce a small, statistically non-significant weight loss in overweight or obese adults. Because the amount of weight loss is small, it is not likely to be clinically important. Green tea had no significant effect on the maintenance of weight loss. Of those studies recording information on adverse events, only two identified an adverse event requiring hospitalisation. The remaining adverse events were judged to be mild to moderate.