the diseases, type 2 diabetes, obstructive sleep apnea,

 the objective is to
see weather green tea is helpful in weight reduction or not.


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Reviewing the basic English language studies published in
2002, 2004,2006.


 Randomized, double
blind, placebo-controlled trials to compare Green tea extracts for weight loss
various online sources including Ovid MEDLINE, PubMed, and Cochrane databases


In each of the three studies subjects were  baseline measurements were taken and
analysed.measuremnets of Total body weight,BMI with reference to age,hip and
waist circumference were measured at the interval of 4 week i.e 0 week,4 week,8
week,12 week


All the RCT’S analysed and reviewed showed the apart of some
minor changes no major changes were observed to prove the significance of green
tea as a sole ingredient for weight increase in body energy
expenditure was observed with lead to increases in apetite by the subjectsbut
no adverse effect was noted.


After detail reviewing and analysis it was concluded that
green tea does not have any major effect in weight reduction as a sole agent


: Green tea extract, Weight Loss, Weight Reduction,
Overweight, O




Obesity is a medical condition body
has an excess amount of fat leading to potential hazadarous
conditions. obesity can also be defined as body mass index (BMI),
can be calculated by dividing a person’s weight by the square of the person’s
height, if it is above 30 kg/m2,at an average range of  25–30 kg/m2 defined as over weight.some
Asian countries use even less a value as a range. Obesity has a potential
hazard of causing serious medical conditions particularly cardiovascular diseases, type
2 diabetes, obstructive sleep apnea, certain
types of cancer, osteoarthritis and depression.23

Obesity is most commonly caused by a life style with no physical
activity,excessive eating fatty and junk food,and some people also have genetic
suspectibilty. A few cases are caused primarily by genes, endocrine disorders, medications,
or mental disorder.a
misconception that obese people tend to gain more weight even with eating less
is in correct.rather obese people has a higher body energy expenditure than a
person who is same age and height with in normal range of an obese
person body need to maintain a bigger body mass.

Obesity is a condition which could be prevented and treated with
simple dietry modifications.eating behavior and physical activity. Dietary
modifications such as less consumption of fats and higher consumption of high
fiber diet and prevent and treat obesity.

Obesity is one of the major preventable cause of death world
wide, with increasing rates in adults and children.113 In
2015, 600 million adults (12%) and 100 million children were obese. Obesity is
more common in women than men. Athorities
consider it as a major problem faced by people of 21 century and a major draw
back of latest inventions Obesity is stigmatized in
much of the modern world (particularly in the Western world),
though it was seen as a symbol of wealth and fertility at
other times in history and still is in some parts of the world.215 In
2013, the American
Medical Association classified obesity as a disease.1617









 Obesity accounts for
big number of hospital visits. In 2006, 
report stated obesity alone accounted for over 7.6% of office visits.the
caring cost of such people take a toll on the society. Researchers have
suggested that these individual’s medical expenses may have reached as high as
$78.5 billion.

There are a few medications which could be given to people
with serious weight problem not controlled by eating habits and where the
benefit out weights the risk involved.never the less medications them self have
adverse effects can not be neglected. Also, non FDA approved drugs are
available in the market which ahave a lot of serious and complicated side

 While there are a lot
of different options in term of treatment, patients often want to hav e
convenient, cost effective, and simple methods to aid their problem. Tea is
historically used as a medication.especially in Asian countries like china and
japan a lot of medicational use odf tea are described in details.Green tea
contain two very important components which are often published as a solution
for weight green tea is a natural supplement if it could be the
solution than it will be the safest and easiest way


The objective is to analyse green tea for its effectiveness
in weight reduction.


 The selected three
studies met the same criteria of subjects as women and men ,who were obese and
were in the age group of 18- 40. Green tea extract was prepared in a capsule
form. The treatment groups were compared to control groups given visually
matched placebo.parameters  including
body weight, body mass index, waist circumference, and hip circumference were
measured . The studies were double blind, randomized, and placebocontrolled.
The study performed by Auvichayapt et al took place at Khon Kaen University in
Thailand.selected participants were students of medicine faculity.the
participants gave informed concent for the research.they were instructed to
maintain their usual dietry and daily habits.and a capule were given for them
to be taken one hour after each meal .time was specified to maintain
compliance. The study performed by Diepvens et al was located in Maastricht,
The Netherlands at Maastricht this research selection of
participants was done via an advertisement in a local news paper for the
willing first subjects were guided to make a chart of their daily
food intake to measure the average amount of caloric intake by the
subjects.than after calculating average caloric intake by each person they were
told to keep their food intake in the range.and continue their daily routine.
Hsu et al conducted the trial at Taipei Hospital, Taiwan for one full year.A
trial of hundered subjects was performed.after selection subjects were given
instruction s about their eating habits and an informed consent was taken.A
capsule was given to each subject and they were required to come after every
month. Some inclution and exclution criterias was followed by all three
studies.Auvichayapat et al included female whome were one year postmenopausal
and male at an average age of 40-50, body mass index of 26 kg/m2 or greater.
Subjects having a history of any metabolic or systemic disease or on daily
medications,and energy expenditure of greater than 8373.6 kJ/day, or specific
history of tea and green tea hypersensitivity were not included. Dievpens et al
included females 18 to 50 years of age with a body mass index of 28 kg/m2 to 35
kg/m2.initial screening was done and subjects who was of good health no
systemic and metabolic disease ,moderate tea and coffe intake and minimum
alcohol intake were  selected. Inclusion
criteria for Hsu et al included females ages 14 -55 and a body mass index of 23
kg/m2 or greater.subjects with endocrine disease, heart disease, allergy or
immunology diseases, high liver or renal enzymes, pregnant or lactating
females, childbirth within six months, stroke history,inability to exercise
were excluded. Key words used in literature searched were green tea, weight
loss, weight reduction, overweight, and obese. All articles searched were
published in peer-reviewed journals in the English language. All literature
searches were performed using Ovid MEDLINE, PubMed, and Brown, Green Tea &
Weight Loss 5 Cochrane Databases. Inclusion criteria for the review were POEM,
randomized controlled trials, and studies published in 2005 or later. An
exclusion criterion for the review was combination of green tea with other
substances. The statistics utilized in the studies were p-value, relative risk
increase (RRRI), absolute risk increase (ARI), and numbers needed to harm


1- Demographics of included studies


        Type   # Pts    Age
(yrs)      Inclusion Criteria    Exclusion Criteria             W/D  Interventions  


Auvichayapat  RCT     75      
Males 35-55   Male 35-55yr.        Hx of metabolic disease/   13   
250 GTE   

 Females post-     female post-      Systemic disease                          CAPSULE

                                                  Meno> 1
yr          meno >1yr        Hx of-Prescribed medic-            TIB after all 3

BMI > 25 kg/m2  ines                                                    meals

-Regular exercise

     Ave-energy exp.daily

> 8373.6 kJ/day


       Hx  of tea / caffeine

Allergic reactions



Diepvens,        RCT       50     
25-60            female
(25-50)           health issues                      1       GTE capsule

Heavy smokers

Over weight,BMI       reg
medicines use

                  ,     Double                                   btw 20-35
kg/m2       allergic

ini.screening               heavy
alcohol use

caffeine >250-450/






Hsu,                  RCT)          150     15-55   
     Females(15-55yr)  cardiac disease                       2     GTE capsule                             

BMI> 28 kg/m2       endocrine

Double                                                                       pregnancy




                    Weight control

Ent in 3 months

                      Other cond
unsuitable as                                                                                                                                                                                                                 



Out come Measured :


The primary out come showed a change I baseline body weight
parameters in all three studies. Body weight parameters are here defined as
body weight, body mass index, waist circumference, and hip circumference.
Quantitative measurements were calculated in percent reduction in all
parameters at different time intervals throughout the intervention.all the
measurements were standertised by conducting them in fasting state of the
subject in all three studies.secondary outcomes were also recorded by all three
studies as well. Auvichayapat et al measured hunger and fullness on visual
analogue scales, resting energy expenditure and substrate oxidation, blood
pressure and heart rate, urine vanillylmandelic acid levels, and leptin
levels.1 Diepvens et al measured systolic and diastolic blood pressure changes
and also changes in blood parameters such as TG, LDL, HDL, leptin, and glucose
levels.2 Hsu et al measure hormone peptide levels throughout intervention
including insulin, adiponectin, leptin, and ghrelin.3




 The results concluded
after the the study was made as a continuous data. The continuous data in the
Hsu et al study can be converted to dichotomous form. The data from the studies
was presented as an intention to treat analysis with the exception of
participants who withdrew or were lost to follow-up. Auvichayapat et al
reported weight loss of 2.5 kg and 1.8 kg in the green tea extract and control
groups, respectively. The p-value over time was statistically significant
between groups (p < 0.05). During this study, side effects were not seen in both controlled and experimental groups. Therefore, exact value which can be harmful can not be calculated. (Table 2). Diepvens et al reported weight reduction of 4.0 kg and 4.5 kg in green tea extract and control groups, respectively. The data is statistically significant (p < 0.001). in the time period of study both groups had no side effects,so no value can be given which may produce harm. (Table 2).       Hsu et al reported weight loss of 0.2 kg and 0.1 kg in green tea extract and control groups, respectively. The data was not statistically significant (p = 0.72). The absolute risk increase (ARI) was calculated to be 0.5% and the relative risk increase (RRI) was calculated to be 0.04%. in this study non of the subjects withdraw from the experiment but their was some subjects whom observed side effects of the a number which could be harmful was concluded. This study determined that the number needed to harm (NNH) was 25 patients using the dosage of 400 mg TID (Table 2).       Table 2- Efficacy of Green Tea Extract in Weight Reduction Study             GTE group           Placebo                   p-value            RRI           ARI            NNH                        Reduction in       group                        Parameters          reduction in                                                     parameters     Auvichayapat, 2.5                       2.1                          <0.05                0*               0*              0* 2005     Diepvens,         4.2                         4.1                       <0.001                0*               0*               0* 2007                                                                                          Hsu, 2008        0.3                          0.2                         0.73                  0.5             0.03            26   GTE=Green tea extract, RRI= relative risk increase, Absolute risk increase, NNH= number needed to harm #= Reported in kilograms lost from baseline weight *Reported that there were no adverse effects in this study **Reported that there were no adverse effects in this study     One of the three trail  showed subjects with mild adverse effect.In Hsu et 4 subjects experienced mild constipation and 2 experienced abdominal discomfort.three subjecys were found to experience mild nausea but no vomiting or other abnormalities were present in placebo treatment. In all three trails subjects were monitored in their special facilities where weight parameters were taken with accuracy and same measuring tools were used through out.screening days were also specified. Auvichayapat et al measured subjects body weight parameters at weeks 0, 4, 8, and 12.1 Diepvens et al had subjects to come on days 0, 12, 36, and 86.2 Hsu et al only measured the subjects on the initial day 0 and after 1 month. Hsu et al also had subjects who missed the follow up.       Tea has historic significance with Green tea gaining wide popularity with its advertisement as a weight reducing agent.It is made from the leaves of  Camellia sinensis,. Camellia sinesis under go very minimum oxidation in the process,containing two very important constituents : catethine polyphenol and caffeine .catethine polyphenol is involved in inhibinting an enzyme catechol-o-methytransferase which in turn leads to very long action of catechoamines. Caffeine is also involved in inhibiting phosphodiesterase induce degradation of Camp which cause an increase release of norepinephrine.both caffeine and catethin polyphenol has increases the energy expenditure which in turn can increase fat oxidation leading to decrease in body weight.catecholamines may also have an important role in satiety as well.   Ll the three used females as their primary subjects with Auvichayapat et al the only study which also use men in their trail.All three studies used Green tea in an extract capsule form.the specific timing and amount og extract used were slightly different. All placebos used are same and used capsule of cellulose. Diepvens et al also allowed their subjects to use caffeine during the trail period.The number of subjects used in all three studies was kept under hundred and trail lasted for about three months.while blimding was not compromised in all the three studies.   CONCLUSIONS By reviewing all the three studies it can be concluded that green tea does have some effect on weight reduction but it is not very significant.and significant variability between the intervention and placebo  can not be well defined.Green tea extract use was unharmful all through the trail further confirming the idea that it is not harmful for the body,but its weight reducing properties has to be further confirmed. More research and investigation is also needed to determine the exact role of energy expenditure increase with the use of green tea.All the three above trails were done for a short duration of time.To further evaluate this property if trails of are lenghter along with control of daily caloric intake and physical activity can give different results. Long term research with more participants and with better follow up protocols the exact statics for this benefical effect of green tea can be concluded, which would be of great help through a natural resource for weight reduction of the over weight. . References 1. Auvichayapat P, Prapochanung M, Tunkamnerdthai O, et al. Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial. Physiol Behav. 2008;93(3):486- 491. 2. Diepvens K, Kovacs EM, Vogels N, Westerterp-Plantenga MS. Metabolic effects of green tea and of phases of weight loss. Physiol Behav. 2006;87(1):185-191. 3. Hsu C, Tsai T, Kao Y, Hwang K, Tseng T, Chou P. Effect of green tea extract on obese women: A randomized, double-blind, placebo-controlled clinical trial. Clinical Nutrition. 2008;27(3):363-370. 4. Obesity and Overweight. World Health Organization. 2010. Available at: Accessed Sept 27, 2010. 5. Overweight and Obesity. Centers for Disease Control. 2010. Available at: Accessed Sept 27, 2010. 6. Cherry, D, Hing, E, Woodwell, D, et al. National Ambulatory Medical Care Survey: 2006 Summary. National Health Statistics Reports. 2008. Available at: Accessed Sept 28, 2010


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