Green tea is often referred to as a superfood.
It is loaded with antioxidants that can help prevent health problems, including cancer ( 1).
Asians have been drinking green tea for centuries ( 2).
In the United States, however, black tea has traditionally been more popular ( 3).
Black tea and green tea are both made from the Camellia sinensis plant.
To make green tea, the plant is is processed quickly to avoid fermentation.
The processing of black tea results in an extra step that oxidizes the plant and removes some of the compounds that make green tea so beneficial ( 3).
What you might not know is that green tea can also help you lose weight.
It's not just hype; researchers have evidence that green tea is more than just hot water.
If you have an unhealthy lifestyle, green tea won't miraculously make you thin.
However, in combination with what you eat, it can help you lose weight in a few different ways.
Green tea contains compounds that can help your body burn energy more efficiently. These compounds include caffeine and catechins.
Although drinking green tea doesn't give you quite the same caffeine boost as consuming a cup of coffee, the caffeine in green tea does have some fat-burning effects.
Green tea contains about 24 to 48 mg of caffeine per 8-oz. serving, depending on the type of tea and the strength at which it's brewed ( 4).
Coffee contains closer to 100 mg of caffeine per cup at minimum.
Caffeine has been extensively studied for its ability to help individuals lose weight.
Studies show that it can speed up the rate that the body burns calories even at rest. Caffeine can also help the body use fat for energy ( 5).
One study showed that among high caffeine consumers and low caffeine consumers, green tea was beneficial in helping them lose weight, inches around the waist and body fat ( 6).
Once they reached their goal weight, however, those who consumed more caffeine had a better chance of keeping it off.
Catechins, some of the antioxidants in green tea, contribute to the beverage's health-boosting effects ( 7).
One catechin, epigallagocatechin gallate (EGCG), is especially effective in increasing your body's ability to burn calories.
This is particularly true when it is combined with caffeine ( 3).
Green tea catechins are absorbed in the digestive tract. However, they affect different people's bodies in different ways ( 8, 9).
The burning of fat for energy is a complex process that involves oxidation and mobilization of fat from the cells.
Fat is stored as triglycerides primarily in adipose tissue ( 10).
As the body requires fuel for energy, the fatty acids stored in these cells can be mobilized and used by surrounding tissues.
Epinephrine and norepinephrine are two hormones that stimulate this mobilization.
Norepinephrine signals the fat cells to break down fat.
Studies show that EGCG helps suppress catechol O-methyl-transferase, an enzyme that metabolizes norepinephrine.
With norepinephrine levels inhibited, the body is not able to use stored fat as effectively for fuel ( 11).
On the other hand, when catechol O-methyl-transferase is suppressed, norepinephrine levels increase ( 12).
Caffeine works in conjunction with EGCG to enhance the effect of norepinephrine on fat cells ( 13), resulting in an higher break down of body fat.
The free fatty acids then become available to other tissue, like the muscles. In fact, when resting, the muscles use primarily fatty acids for fuel ( 14).
Because green tea makes free fatty acids more readily available, your body can burn more fat even when you're sleeping.
Your basal metabolic rate (BMR), is the rate at which your body burns calories just to do things like breathe and hold itself up.
The body is like a machine. Your cells are constantly performing complex functions just to keep you alive and healthy.
These functions require fuel.
One study found that healthy participants who took green tea extract experienced a 4% higher calorie burn in a 24-hour period than participants who took no supplements or who consumed caffeine alone ( 15).
Another study found significant increases in 24-hour energy consumption in participants taking a supplement that contained the caffeine equivalent of a cup or two of coffee and varying levels of EGCG ( 16).
What was interesting in this study was that the amount of EGCG did not seem to have an effect on the increased calorie burn.
This suggests that even small amounts of EGCG added to the diet can increase your basal metabolic rate.
Additional research supports the findings of about 4% increased calorie burn with the administration of green tea extract, especially when the supplement was combined with a healthy diet ( 17, 18).
While this doesn't necessarily allow you to eat an extra hamburger a day without gaining weight, it could help someone whose BMR is 1500 burn 60 more calories per day.
This could have significance for long-term weight maintenance when accompanied by a healthy diet.
Because habitually consuming high levels of caffeine can actually have no effect when it comes to weight maintenance after weight loss, green tea drinkers may have an advantage.
Studies show that people who don't typically consume a lot of caffeine have better luck managing their weight when they supplement with a green tea-caffeine mixture ( 19).
The effects of green tea extract on BMR also depends on the individual's body chemistry and lifestyle ( 20).
Many fat-burning supplements contain catechins and caffeine.
They also typically contain ephedrine, which is similar to epinephrine.
Green tea helps the body naturally release more epinephrine, as discussed above.
I told you how green tea helps your muscles use fat for fuel while at rest.
It has also been shown to enhance your body's ability to burn fat while exercising too.
Not surprisingly, norepinephrine is released when you exercise. Green tea increases norepinephrine levels in the body.
Can you see where I'm going with this?
Some researchers found that men who consumed green tea extract burned almost 20% more fat than those who weren't taking the extract ( 21).
Other researchers found that green tea increased the body's ability to burn fat while exercising and at rest ( 22).
Many other studies back up these findings.
Compounds in green tea target fat cells, and drinking green tea over the long term can help reduce body fat ( 23, 24).
In addition to helping you burn more fat while you exercise, green tea can help you exercise for longer periods of time.
If you can exercise longer, you may burn more calories.
Researchers attribute the increase in endurance to the muscles' ability to use free fatty acids for fuel.
The EGCG in green tea extract plays a major role in facilitating this ( 25).
Many studies also point to caffeine as an endurance booster ( 26, 27, 28).
When people consume caffeine before exercising, they may be able to work out longer before becoming fatigued.
Their perception of pain also diminishes.
Studies show that substances that help you burn more fat tend to reduce appetite at the same time ( 29).
In addition, one study showed that this effect was improved when the dietary levels of fats were high ( 30).
Perhaps drinking green tea can help prevent you from overeating, especially if you're consuming enough healthy fats with meals.
Researchers have looked into this, but they have come up with inconsistent results ( 31, 32, 33).
In one study, rats injected with EGCG lowered their food consumption by 50 to 60% ( 34).
However, studies that have looked at oral ingestion of green tea catechins have not proven that you'll eat less if you consume green tea ( 35).
Still, most of these studies were conducted on animals.
Not enough studies on humans have been conducted to determine a clear answer to whether green tea can help reduce appetite ( 31).
It is possible that green tea may decrease nutrient absorption in the intestines.
Studies on humans and rats have shown blood glucose levels are lower after the administration of a glucose tolerance test when subjects take oral EGCG and green tea catechins ( 36, 37, 38, 39).
Green tea may also lower the amount of dietary fat that the body absorbs.
However, these studies have only been conducted in animals and in vitro, not in humans ( 35, 40, 41).
It looks as though green tea helps the body burn calories, but it may not affect the number of calories that you take in.
However, swapping out a soda or high-calorie beverage for green tea can help you consume fewer calories during the day.
Although you might not lose a significant amount of weight from drinking green tea, you can lose the most dangerous type of fat.
Excess abdominal fat increases the risk of dying from several health conditions ( 45).
Most people lose about three pounds on average from consuming green tea or extract ( 42, 43).
However, much of the fat lost is visceral abdominal fat, the type that can surround organs and lead to dangerous health conditions like type 2 diabetes and cardiovascular disease.
With more than one-third of American adults falling in the obese range, researchers have begun looking into green tea as a possible treatment and mediator ( 44).
One study had participants who were generally healthy drink a beverage that contained about 625 mg of catechins per day.
The group that consumed catechins lost more weight than the control group ( 46).
Although reduction in waist circumference remained the same in both groups, the catechin group lost more total abdominal fat and subcutaneous abdominal fat after 12 weeks.
Another study found that participants lost inches around the waist as well as visceral and subcutaneous fat after taking green tea that contained 583 mg of catechins for 12 weeks ( 47).
Another study looked at participants who already had a high proportion of visceral fat.
The loss of visceral fat, body fat in general and body weight was greater in the group that consumed catechins ( 48).
Green tea may be an ideal natural way to supplement a healthy diet and active lifestyle in order to keep your metabolism up and manage your weight.
Although it's not a miracle weight-loss solution, it can increase metabolism and increase your body's ability to burn fat, especially while you exercise.
Drinking green tea or taking green tea supplements with food can prevent the beneficial catechins from being absorbed into the bloodstream ( 49).
Therefore, you preferably drink it on an empty stomach.
The body is better able to use the green tea catechins from supplements than from drinking green tea ( 8, 9).
If you want the most significant results, you might consider taking a supplement or an extract instead of drinking the beverage.
However, simply drinking green tea every day has a whole host of other benefits for your health.
Green tea can be an extremely beneficial addition to your diet.
