Water is the only beverage that's more widely consumed than tea, according to the Linus Pauling Institute at Oregon State University. Although people usually make tea by steeping dried tea leaves in boiling water, you can also make tea by dissolving matcha powder -- which is made from finely pulverized green tea leaves -- in hot water.
With its dense green color and frothy finish, matcha tea looks more like wheatgrass juice than traditional green tea. Because you ingest the leaf itself, matcha-based drinks are more flavorful – and substantially more nutritious – than regular infusions. One major tea company calls matcha powder a calorie-free food, but another supplier claims that it contains 3 calories per gram. Either way, the average cup of matcha tea provides very few calories.
Matcha is a highly concentrated source of catechins, which are the antioxidants responsible for most of the health benefits associated with green tea. If you're looking to get more antioxidants without boosting your caloric intake, however, you're probably better off sticking with homemade matcha. Many of the matcha-based beverages available in cafes are high in calories and sugar. The "green tea latte" made with matcha that a major coffee chain offers delivers 175 calories and 28 grams of sugar per 8-ounce cup.