Contains Substances That Can Help You Lose Fat

Tea leaves contain many beneficial compounds.

One of green tea’s compounds is caffeine. Although a cup of green tea holds much less caffeine (24–40 mg) than a cup of coffee (100–200 mg), it still contains enough to have a mild effect.

Caffeine is a well-known stimulant that has been found to aid fat burning and improve exercise performance in numerous studies (1, 2).

However, green tea really shines in its antioxidant content. Studies show that drinking a cup of green tea increases the amount of antioxidants in your bloodstream (3).

This healthy beverage is loaded with potent antioxidants called catechins (4).

The most important of these is epigallocatechin gallate (EGCG), a substance that can boost metabolism.

Although one cup of green tea may raise your antioxidant levels, most studies have examined the benefits of green tea extract — which is a concentrated source of catechins.

SUMMARY Green tea contains bioactive substances like caffeine and EGCG, which can have powerful effects on metabolism.

Can Mobilize Fat From Fat Cells

To burn fat, your body must first break it down in the fat cell and move it into your bloodstream.

Animal studies suggest that the active compounds in green tea can aid this process by boosting the effects of some fat-burning hormones, such as norepinephrine (noradrenaline).

The main antioxidant in tea, EGCG, can help inhibit an enzyme that breaks down the hormone norepinephrine (5).

When this enzyme is inhibited, the amount of norepinephrine increases, promoting fat breakdown (6).

In fact, caffeine and EGCG — both of which are found naturally in green tea — may have a synergistic effect (7).

Ultimately, your fat cell breaks down more fat, which is released into your bloodstream for use as energy by cells like muscle cells.

SUMMARY Compounds in green tea increase levels of hormones that tell fat cells to break down fat. This releases fat into the bloodstream and makes it available as energy.

Increases Fat Burning, Especially During Exercise

If you look at the label of almost every commercial weight loss and fat-burning supplement, you will likely see green tea listed as an ingredient.

This is because green tea extract has been repeatedly linked to increased fat burning, especially during exercise.

In one study, men who took green tea extract before exercise burned 17% more fat than men who didn't take the supplement. The study suggests that green tea can boost the fat-burning effects of exercise (8).

An eight-week study determined that tea catechins increased fat burning, both during exerciseand rest (9).

Several other studies confirm these findings, indicating that EGCG boosts the burning of fat — which may lead to reduced body fat in the long term (10, 11).

SUMMARY A number of studies show that green tea extract can boost fat burning. The effect is even stronger during exercise.

Boosts Your Metabolic Rate

Your body is constantly burning calories.

Even when you’re sleeping or sitting down, your cells are performing millions of functions that require energy.

Several studies suggest that taking green tea extract or EGCG supplements can make you burn more calories — even at rest.

In most studies, this amounts to about a 3–4% increase, although some show an increase as high as 8% (12, 13, 14).

For a person who burns 2,000 calories per day, 3–4% amounts to an additional 60–80 calories spent per day — similar to what you might expect from a high-protein diet.

Although most of these studies were very short in duration, some evidence suggests that the metabolism-boosting effect persists in the long term (15, 16).

In one study in 60 obese individuals, those taking green tea extract lost 7.3 more pounds (3.3 kg) and burned 183 more calories per day after three months than those not taking the extract (17).

However, not all studies show that green tea extract boosts metabolism. The effect may depend on the individual (18).

SUMMARY Several studies suggest that green tea can boost metabolism and help people burn 3–4% more calories each day.

Can It Automatically Make You Consume Fewer Calories?

One way that green tea could aid weight loss is by reducing appetite.

This would theoretically make you consume fewer calories automatically — and without any effort.

However, studies produced conflicting results on the effects of green tea on appetite (19).

Some animal studies suggest that green tea extracts or EGCG supplements can reduce the amount of fat you absorb from foods, but this has not been confirmed in humans (20, 21, 22).

Overall, green tea’s primary effect is to increase calorie expenditure, making you burn more fat — but it doesn't appear to have any noticeable effect on how much food you end up eating throughout the day.

SUMMARY  There is currently no evidence that green tea makes people eat fewer calories. Some studies in animals suggest that it may reduce the absorption of fat from the diet, but human studies have not confirmed this.

Green Tea Can Help You Lose Fat, Especially Harmful Abdominal Fat

When it comes to actual pounds lost, the effects of green tea are relatively modest.

Although many studies show that people do in fact lose weight, there are also some studies showing no effect.

Two reviews of many controlled trials on green tea supplements found that people lost about 3 pounds (1.3 kg) on average (23, 24).

Keep in mind that not all fat is the same.

Subcutaneous fat lodges under your skin, but you may also have significant amounts of visceral fat, also called belly fat.

High amounts of visceral fat are associated with inflammation and insulin resistance, both of which are strongly linked to several serious diseases, including type 2 diabetes and heart disease.

Several studies on green tea catechins show that although the weight loss effects are modest, a significant percentage of fat lost is harmful visceral fat (25, 26, 27).

Therefore, green tea should reduce your risk of many major diseases down the line, which may lead to a longer and healthier life.

SUMMARY Green tea extract or catechin supplements may help you lose visceral fat — a fat that is particularly harmful to your health.

The Bottom Line

Even though green tea extract or EGCG supplements can cause a modest increase in metabolic rate and fat burning, its effects are modest when it comes to actual pounds lost.

However, every little bit adds up, and it may work even better when combined with other effective weight loss strategies like eating more protein and cutting carbs.

Of course, don’t forget that the benefits of green tea extend beyond weight loss. It is also healthy for various other reasons.

Keep in mind that most studies have examined green tea extracts or supplements containing isolated green tea antioxidants.

In comparison, the effects of drinking green tea are probably minimal, although regular intake may have long-term benefits.