Green tea has been consumed for centuries for its potential health benefits. In recent years, green tea specifically has been linked to weight loss and weight management. Drinking green tea may support weight loss in a few different ways:
1. Green tea contains caffeine and catechins that may boost metabolism
Green tea contains both caffeine and catechins, substances that may slightly boost metabolism. The combination of caffeine and catechins found naturally in green tea may cause a small increase in energy expenditure and fat oxidation, or the breakdown of fat. Research suggests that drinking 3-4 cups of green tea per day may increase energy expenditure by 4-5%.
This equates to roughly an extra 100 calories burned per day from green tea consumption. While an extra 100 calories per day is small, it could contribute to weight loss over time or help counteract weight gain.
2. EGCG in green tea may inhibit fat absorption and increase fat burning
Green tea is rich in a catechin called epigallocatechin gallate (EGCG). EGCG is an antioxidant that has been shown in some animal studies to reduce fat absorption and increase fat burning when combined with low doses of caffeine.
However, human studies testing the direct effects of EGCG on weight loss have been inconclusive. Overall, more research is needed on how EGCG from green tea supports weight loss in humans.
3. Drinking green tea may suppress appetite
Some research has found that green tea may help suppress appetite by slowing digestion and promoting feelings of fullness. In one study, overweight men who took green tea extract for 12 weeks experienced reductions in appetite compared to a control group.
The combination of caffeine and catechins in green tea may generally help suppress appetite and reduce calorie intake. However, individual results can vary.
Green tea dosage for weight loss
Most research on green tea for weight loss has used doses of 600–900 mg per day of green tea catechins. The easiest way to consume this amount is by having 3-4 eight ounce cups of green tea per day.
To maximize the weight loss benefits from green tea, it may be ideal to consume a green tea supplement that delivers an optimal dose of catechins. Green tea extract supplements that provide 500-750 mg of catechins like EGCG may support weight loss more effectively than drinking tea alone.
Typical catechin content per cup of green tea:
– Brewed green tea: approximately 50 mg catechins per 8 ounce cup
– Matcha green tea: approximately 100 mg catechins per 1 ounce serving
– Green tea extract capsule: 250-500 mg catechins per capsule
Consuming green tea extract capsules makes it simpler to reach an optimal 500-900 mg daily dose of catechins. However, drinking traditional brewed green tea can also provide weight loss benefits.
Scientific evidence on green tea and weight loss
Many high quality clinical trials have tested the effects of green tea catechins on weight loss and body composition in humans. Here is an overview of the scientific evidence:
Randomized controlled trials on green tea extract
– Women taking a green tea catechin and caffeine supplement for 12 weeks lost on average 1.3 kg more weight and 2.1 cm more from their waistline compared to a control group in one study.
– Men who took a green tea extract capsule for 12 weeks had significantly greater reductions in body fat area, waist circumference, and levels of LDL cholesterol compared to the placebo group in another study.
– Several other randomized controlled trials have found green tea extract supplements to cause modest but significant weight loss, typically in the range of 0.8-3 kg over a 12 week period.
Meta-analyses on green tea catechins and weight loss
Meta-analyses that compile data from multiple studies have concluded:
– Green tea catechins combined with caffeine can significantly reduce body weight compared to caffeine alone.
– Ingestion of green tea extract can induce a small but significant weight loss of 1-3 kg, particularly in people who are overweight or obese.
– The body of research overall supports that green tea catechins and caffeine can induce modest weight loss and have favorable effects on body composition.
Limitations of the research
While many studies show statistically significant though modest weight loss from green tea, some studies have not found significant effects. The weight loss benefits associated with green tea catechins may depend on the:
– Dosage and formulation of green tea extract
– Diet and lifestyle habits of the participants
– Duration of the studies (at least 12 weeks may be needed to see results)
More rigorously designed and controlled studies in humans are still needed to better understand green tea’s effects on weight. But the evidence so far indicates beneficial effects.
How to drink green tea for weight loss
Here are some tips on how to incorporate green tea into your diet to maximize the potential weight loss benefits:
1. Drink at least 2-3 cups per day
To get enough EGCG and caffeine for weight loss, aim for 2-4 eight ounce cups of green tea per day. This will provide at least 100-200 mg of EGCG. Avoid adding milk, cream or sugar so you can maximize tea’s catechin content.
2. Try drinking green tea before a workout
The combination of caffeine and EGCG may make green tea particularly helpful pre-workout. Caffeine provides extra energy while EGCG’s antioxidant effects may help with exercise recovery.
3. Take a green tea extract supplement
Green tea extract capsules provide a concentrated dose of catechins in an easy format. Look for a supplement with 500-750 mg of catechins and take it once or twice per day.
4. Drink a cup of green tea before meals
Drinking green tea just before eating may help suppress your appetite slightly. The warm temperature of tea also adds to its soothing effect.
5. Choose high quality loose leaf or bottled tea
The catechin content of green tea can vary widely depending on the quality. Opt for reputable brands of bottled or loose leaf green tea. Avoid lower quality tea bags.
6. Add lemon to boost the catechins
Adding lemon to your tea may help preserve catechins during brewing, providing a little extra boost.
7. Pair green tea with exercise and a healthy diet
Green tea alone isn’t likely to lead to dramatic weight loss. Combining regular exercise and a diet rich in fruits, vegetables, whole grains, and lean proteins will maximize results.
Is drinking 3 cups of green tea per day safe?
For most healthy adults, drinking 3 cups of green tea per day is considered safe and should not cause negative side effects. However, there are a few considerations:
– Caffeine content
Each cup of green tea has about 25-50 mg caffeine. Consuming 75-150 mg caffeine daily from green tea is not excessive for most people. But it’s smart to limit caffeine from other sources like coffee when drinking 3 cups of green tea daily.
– Effects on iron absorption
The EGCG in green tea may somewhat inhibit iron absorption, especially when drinking tea around meals. Those with low iron levels should avoid having green tea alongside iron-rich foods.
– Anxiety and sleep issues
The caffeine in green tea may cause problems with anxiety or sleeplessness if consumed late in the day, especially by sensitive individuals. It’s best to avoid green tea after 2 pm.
– Interactions with medications
The caffeine in green tea may interact with some medications including MAO inhibitors, diuretics, and stimulants. Check with your doctor about potential reactions.
– Pregnancy and breastfeeding
Up to 2 cups of green tea per day is considered safe if pregnant or breastfeeding. Avoid taking green tea supplements without medical approval.
– Children and teenagers
Green tea is not recommended for toddlers. Older children and teenagers should limit intake to 1-2 cups of green tea daily due to the caffeine content.
Overall, 3 cups of green tea per day is safe for most adults and has more health benefits than risks. But it’s wise to be mindful of your individual caffeine sensitivity.
Possible side effects of green tea
Green tea consumed in normal amounts is generally well tolerated by most people. But minor side effects are possible, especially when drinking 3 or more cups per day. Potential side effects can include:
– Headaches
– Irritability
– Anxiety or nervousness
– Insomnia
– Increased heart rate and blood pressure
– Diarrhea or upset stomach
– Dizziness
– Tremors
– Nausea
– Vomiting
The caffeine content of green tea is the most likely cause of adverse effects. Very high intakes of EGCG from supplemental doses of green tea extract may also contribute to side effects like nausea or stomach pain in some individuals.
If you experience discomfort, consider decreasing your green tea intake or stopping consumption altogether. See a doctor if severe side effects develop.
Special considerations for green tea
While moderate green tea intake is healthy for most people, the following groups should take extra precautions:
Pregnant or breastfeeding women
Up to 2 cups of green tea per day seems to be safe during pregnancy and breastfeeding. Green tea supplements are not recommended.
Those sensitive to caffeine
If you find even small amounts of caffeine disruptive, limit green tea intake to 1 cup per day or every other day.
People taking prescription medications
Speak with your doctor about potential interactions with green tea. Certain blood pressure, diabetes, anxiety and stimulant medications may interact.
Those with anemia or low iron
Avoid drinking green tea with meals if you are prone to iron deficiency. Green tea could inhibit some iron absorption.
Children and teenagers
Green tea is not recommended for toddlers under 18 months old. Older kids and teens should limit green tea to 1-2 cups per day.
Those with anxiety disorders
The caffeine in green tea may aggravate anxiety symptoms. Monitor your reactions and adjust your intake accordingly.
Individuals with heart conditions
Caffeine could increase heart rate and blood pressure. Consult your cardiologist about green tea if you have a heart condition.
If you have any ongoing health concerns, it’s wise to check with your doctor before making green tea a regular habit.
Conclusion
Research shows green tea and its active ingredients like EGCG may provide modest weight loss benefits of approximately 1-3 pounds over 12 weeks. Drinking 3 cups of green tea per day seems to be adequate for weight loss effects and is safe for most healthy adults.
To experience the optimal weight loss results from green tea, aim for at least 500-750 mg catechins like EGCG daily from either brewed green tea or a green tea extract supplement. Combining green tea intake with regular exercise, a healthy diet, and other weight control measures can maximize your results. While not a miracle solution, green tea is an accessible and healthy addition to a weight loss program.
