Green tea has the power to help you lose weight. It has the power to shift your metabolism into high gear but how far does this power reach? What kinds of green tea should you drink? Is green tea extract effective? Does temperature affect potency? So many questions, and finally some answers. Registered dietitian and Women's Health's nutrition expert Keri Glassman had all the answers. Do you get the same green tea benefits with flavored green teas? "The benefits of green tea shouldn't be lessened by the addition of flavors," says Glassman. However, if the flavouring includes sugar, it may contain more calories than the unflavoured tea. Avoid green teas with added sugar or artificial sweeteners. Does the brand of green tea matter? Yes, it does. "There can be a difference in the quality of tea leaves and the number of additional, unnecessary ingredients," Glassman says. When you are checking labels, keep in mind that green tea is not a significant source of vitamins. Look for brands that use all natural ingredients and no artificial preservatives. What if the green tea is iced? It is the same as green tea, just colder but keep in mind that it can also be diluted with water. The weight loss benefits are maximized when served hot. Remember this tip: don't let the water come to a full boil. Instead, pour the water over the tea bag right before it boils (the point where tiny bubbles begin to form). Then, let the tea steep for about 2-4 minutes. Can green tea go bad? It won't spoil but, like with most food, the fresher, the better, Glassman says. "If using loose tea or tea bags, make sure to [drink up] within six months." If you don't, the tea will lose some of its antioxidant properties. If I'm not in a "tea mood," will a green tea extract do the trick? Great news, the answer is yes! "Adding green tea extract to water is a great way to get the benefits of green tea while on-the-go," Glassman says. "Depending on the concentration of the formula, 1 ml of green tea extract can allow you to reap the benefits of drinking roughly 8 to 10 cups worth of antioxidant-rich green tea." Tea time, anyone?