Green tea is one of the most popular beverages around the world, well known for its potential health benefits. One area of interest is whether green tea can help with weight loss. This article examines the evidence surrounding green tea and weight loss.
Can Green Tea Help You Lose Weight?
There is some evidence from human studies that green tea can boost metabolism and help burn fat. However, most of this research has been in overweight and obese adults.
One review of 14 human studies found that drinking green tea was linked to decreases in both body weight and body fat. However, the weight loss effects were modest, with an average loss of 0.2 to 3.5 pounds over 12 weeks (1).
Other research shows that drinking green tea may support weight loss by:
- Increasing fat burning, especially during exercise (2, 3).
- Improving insulin activity and blood sugar regulation (4).
- Reducing appetite (5, 6).
The main antioxidant in green tea called EGCG has been shown to increase the breakdown of fat, particularly the dangerous visceral fat that accumulates around organs (7, 8).
How Green Tea Boosts Metabolism and Fat Burning
Green tea contains caffeine and a type of flavonoid called catechin, which both have been shown to help with weight loss. These compounds may have several metabolism and fat burning effects (1, 9, 10):
- Caffeine stimulates the nervous system, signaling fat cells to break down fat. It also increases epinephrine (adrenaline) levels in the blood, which tells the body to start burning fat for fuel (11, 12).
- Catechins, especially EGCG, boost metabolism and increase fat burning, particularly during exercise (13, 14).
- Caffeine and catechins promote the breakdown of fat and increase the amount of fat released from cells into the bloodstream (15, 16).
- Catechins block the enzyme that breaks down adrenaline. This prolongs adrenaline’s fat burning effects (17).
- Catechins reduce the digestion and absorption of dietary fat and carbs (7, 18).
- Caffeine and catechins may improve insulin sensitivity and blood sugar control (19, 20).
Better insulin sensitivity and lower blood sugar can increase fat burning and make it easier to lose weight or keep it off (21).
How Much Caffeine is in Green Tea?
An 8-ounce (230 ml) cup of green tea contains between 30 and 50 mg of caffeine. This is about one-third the amount in a cup of coffee, which provides 80–135 mg (22, 23).
Decaffeinated green tea only contains about 2–10 mg of caffeine per cup. This tiny amount is unlikely to produce significant weight loss effects.
How Many Cups per Day to Lose Weight?
Most of the weight loss benefits of green tea are linked to compounds like caffeine and EGCG, which have been shown to rev up metabolism.
To get the fat burning benefits of these compounds, you need to drink sufficient amounts of green tea.
Studies showing weight loss effects used 3–5 cups per day, providing 240–1250 mg of catechins and 90–150 mg of caffeine (24).
For reference, an 8-ounce (230 ml) cup of green tea contains about 25–50 mg of catechins. So 3–5 cups per day would provide 75–250 mg (25).
Based on current research, the minimum effective amount of green tea seems to be 2–3 cups per day. Ideally, to lose weight, aim for 3–5 cups spread throughout the day for the best results.
Green Tea Dosage for Weight Loss
Here are general green tea dosage recommendations based on the research:
- Minimum: 2 cups per day
- Better: 3–5 cups per day
- Maximum: 10 cups per day (above this likely won’t increase benefits)
To maximize the fat burning effects of green tea:
- Use loose leaf tea instead of tea bags
- Allow the tea to steep for 3-5 minutes
- Drink it while hot or cold, not lukewarm
- Drink it without added sugar, honey or milk
How Much Weight Can You Lose?
Most weight loss from drinking green tea is minor, generally averaging 0.5–3 pounds over 12 weeks. However, some studies suggest more significant effects:
- One review found an average weight loss of 2.9 pounds (1.3 kg) over 12 weeks for people drinking green tea without other dietary changes (26).
- Another study had participants drink four cups per day. They lost an average of 4.4 pounds (2 kg) over 8 weeks, compared to no weight change in the control group (27).
- An analysis of 15 human studies using green tea preparations for weight loss found an average weight loss of 2.9 pounds (1.3 kg) over 12 weeks (1).
Overall, this data suggests drinking green tea can support moderate weight loss, but effects will vary between individuals.
Other Benefits of Green Tea for Weight Loss
Aside from the direct effects on fat burning and metabolism, green tea may help weight loss and fat loss in other ways, including:
- Appetite suppression. Compounds in green tea like EGCG and caffeine may reduce appetite. This could lead to reduced calorie intake (5, 6).
- Lower calorie intake. The catechins in green tea may inhibit enzymes that break down starches into simple sugars. This could cut carb and calorie absorption from meals (7, 18).
- Increased fat burning during exercise. The catechins and caffeine in green tea may prolong the effects of adrenaline. This could lead to increased fat burning, particularly during exercise (3, 13).
Health Benefits of Green Tea
Aside from potential benefits for weight loss, drinking green tea has been linked to many other health benefits:
- Reduced risk of heart disease and stroke (28, 29)
- Lower cholesterol levels (30)
- Decreased blood pressure (31, 32)
- Improved blood sugar control and insulin sensitivity (33, 34)
- Reduced risk of type 2 diabetes (35, 36)
- Slower decline in brain function (37)
- Lower risk of dementia, Alzheimer’s and Parkinson’s (38, 39)
- Decreased risk of certain cancers (40)
Drinking green tea is a simple habit to increase antioxidant intake and improve overall health and wellbeing.
Possible Side Effects
Green tea is generally well tolerated with few side effects. However, drinking too much green tea daily could cause problems:
- Caffeine-related side effects: Restlessness, tremors, insomnia, irritability, headaches and heartburn (41).
- Iron deficiency: Green tea can inhibit iron absorption. Those with low iron levels should avoid drinking it with meals (42).
- Manganese toxicity: The tea plant is high in manganese, which can accumulate to toxic levels. Those with liver disease are advised to drink no more than 3 cups per day (43).
Green tea supplements containing high doses of EGCG and caffeine should be avoided, especially by pregnant women.
Children and pregnant or breastfeeding women should not consume more than 2 cups of green tea daily.
How to Prepare Green Tea for Weight Loss
To maximize the fat burning potential and weight loss benefits of green tea, it’s best consumed plain without additives like sugar, milk or cream:
- Use 1 teaspoon (2 grams) of green tea leaves per cup of hot water.
- Steep the tea in 80–85°C (176–185°F) water for 1–3 minutes.
- Drink it hot or cold instead of lukewarm.
- Avoid adding milk, sugar, honey or cream as they may counter the benefits.
You can try adding a squeeze of lemon or ginger for flavor instead.
Loose tea leaves allow more catechins and flavonoids to be extracted into the water compared to tea bags. Decaffeinated varieties will provide the benefits of green tea without as much caffeine.
Types of Green Tea
All non-herbal tea comes from the Camellia sinensis plant. The differences come from how the leaves are processed after harvest:
- White: Made from young tea leaves. Minimal processing so the highest in catechins.
- Green: Unoxidized leaves, dried shortly after harvest.
- Oolong: Partial oxidation during processing.
- Black: Fully oxidized leaves, strongest flavor.
For weight loss purposes, green tea provides the most benefits due to its minimal processing and high catechin levels.
Healthy Weight Loss Diet Tips
Green tea can provide fat burning and metabolism benefits to help you lose weight. However, achieving significant weight loss requires other lifestyle changes as well.
Here are some other tips to maximize results on a weight loss diet:
- Increase intake of protein and fiber. Eat 25–30 grams of protein and 30+ grams of fiber per meal.
- Reduce calorie intake by 500–1000 calories per day to create a calorie deficit.
- Cut back on added sugars, refined carbs and unhealthy fats.
- Fill up on whole foods like fruits, veggies, legumes, lean proteins and whole grains.
- Exercise regularly by doing both cardio and strength training.
- Drink plenty of water, ideally 8 cups or more per day.
- Get adequate sleep and reduce stress to optimize hormone levels.
- Consider intermittent fasting by limiting meals to an 8-hour window.
Combining green tea intake with these tips will maximize fat burning and weight loss.
Frequently Asked Questions
Does green tea make you poop?
Green tea has a mild laxative effect and can make you poop more frequently. This is due to the caffeine and a compound called theophylline, which relaxes the muscles in your digestive system (44).
When should I drink green tea to lose weight?
For weight loss, it’s best to drink green tea in the morning before your first meal. This boosts metabolism and increases fat burning for the remainder of the day. Drinking it between meals also provides appetite suppression benefits (45).
Does putting milk in green tea ruin the benefits?
Adding milk to your tea can reduce the absorption of catechins by 25–50%. To maximize health benefits, avoid adding milk, cream or sugar to your green tea (46).
Does green tea burn existing fat?
Compounds in green tea increase the breakdown of fat, mobilize fat from fat cells and increase fat burning. This can help burn existing body fat, particularly harmful visceral fat around the organs (7, 8).
Conclusion
Drinking green tea daily can produce modest weight loss over a period of 12 weeks, on average about 1–2 pounds. Larger amounts, around 4 pounds, are possible but rare.
The majority of the fat burning effects come from the caffeine and catechin antioxidants in green tea, particularly EGCG.
To see benefits, aim to drink around 3–5 cups per day, or a minimum of 2 cups. Drinking it optimally strong, plain and in the morning before breakfast seems to have the most impact.
Combining green tea intake with other diet and lifestyle changes can help you lose additional weight and keep it off long term.
