Now green tea is good for you for many reasons but will it help you lose weight? There was a great 2012 Cochrane review on these, the gold standard of evidence, reviewing 14 different trials from around the world. What did they find?
Those in the green tea extract group lost on average 0.2 to 3.5 kg more than those in the control group over 12 weeks. In most studies, though there was no major effect on weight. Overall, research suggests that taking green tea extract along with caffeine seems to slightly reduce BMI, body weight and waist circumference compared to caffeine alone. But, taking green tea extract without caffeine does not seem to reduce weight.
This evidence does not apply to cups of green tea. All trials used preparations of green tea that involved extraction that yielded concentrations of active ingredients like the catechins and caffeine, that was greater than that produced in a traditional cup of green tea.
Now, this is important because often green tea extract supplements are quite a high dose. And whilst having 1-2 cups of green tea a day is fine, these supplements can be like 10 cups of green tea in one hit. That is a lot for your liver to take and in fact, there have been concerns about these supplements causing serious liver damage, even being fatal at high doses. And lower doses can cause a range of other side effects as well.
So here is just my opinion based on the links below – most sources say it has little effect, so at best you will get an extra 1kg a month weight loss, that is at best and most people won’t get that. You have to buy a supplement for this, maybe $40 a month, and you accept the risks of that, some serious, some annoying. When I weight it up like this, in my opinion for weight loss – I would steer clear of the green tea extract supplements.
Though I do think green tea is overall good for you and a better choice than many other drinks, so a few cups a day is probably all I would recommend