For obese individuals with metabolic syndrome (which I am guessing most obese people have, to some degree or another), drinking green tea resulted in 5 lbs of weight loss in 8 weeks, with no additional lifestyle changes. Most people I know would gladly drink a little extra tea to lose 5 lbs so easily. This is yet more evidence that green tea is mildly helpful in helping a person lose weight. I don’t care for the taste, so I take a green tea extract pill a few times a week before exercise.
I should note that it is probably good that a supplement is only “mildly” helpful in weight loss. If a substance is highly effective at causing weight loss, we have another name for that substance: a poison! This illustrates why the public’s demand for a magic weight loss pill is contrary to our basic biological nature. For hundreds of thousands of years humans evolved to more effectively gain weight (which is why our bodies become more efficient and nearly “shut down” when starved), and yet for the last 50 or so, Westerners are getting too much food. I would be suspicious of a pill that caused dramatic weight loss.