There are plenty of beverages that claim they can help you sip away the pounds, from protein shakes to bone broth to lemon water. But the humble little drink that may be the all-time champion when it comes to weight loss is a cup of green tea.

Green tea, which is brewed from the leaves of the cameillia sinensis plant, has been sipped and enjoyed in China for more than 1,000 years–at least as far back as the 7th century Tang Dynasty. Because the leaves are plucked and cooked immediately, rather than being left to ferment and oxidize like the leaves for black tea, they retain higher concentrations of polyphenols and antioxidants than the English Breakfast or oolong you might sip in the morning before work.

What does this mean for your waistline? Plenty. “Studies suggest that the antioxidants in green tea may promote metabolic health and help reduce appetite,” says Josh Axe, D.N.M., founder of Ancient Nutrition.

The super-powered ingredient is a catechin called epigallocatechin gallate (EGCG), which is believed to increase metabolism and help burn fat.

Here’s why science says it’s so potent:

  • It has the one-two punch of catechins and caffeine: The EGCG and caffeine in green tea may work together to increase weight loss and weight maintenance, says one large study.
  • It can make it easier to zip up your jeans: One Chinese study found that when subjects drank tea that was high in catechins twice a day, they saw a decrease in belly fat, losing an average of 1.9 cm in waist circumference and 2.6 pounds of body weight,
  • It may boost metabolism: Though the evidence is mixed, some research has suggested that the catechins in green tea can help speed up the rate at which your body burns off fat.

Now, this doesn’t mean you can eat whatever you want and then magically burn it all off by sipping some green tea while you catch up on The Crown; green tea is simply one tool you can use to achieve your weight-loss goals, along with a healthy diet and exercise.

But the most important role that green tea may play in your weight-loss is plan is in replacing other beverages, says Dr. Axe. “When you drink unsweetened green tea instead of flavored lattes, juices, or sodas, you are cutting hundreds of calories a day.”