Obesity or overweight is a serious healthcare issue all over the globe. An estimated 1.9 billion people are overweight.
An alarming 600 million of them are obese.
According to medical terms it is the over accumulation of fat in our body- especially in the hip, waist and abdominal region.
It increases the risk of hypertension, type 2 diabetes, high levels of cholesterol and heart diseases.
Tea is a type of beverage (rich in polyphenol) made from dried leaves or leaf extract from the plant Camellia sinensis.
It was first discovered by the Chinese emperor ShenNung in 2737 BCE.
There are various kinds of it. Of them green tea, black tea, white tea and oolong tea are most prevalent varieties.
Teas can also be prepared by steeping various herbs and plants in boiling water in order to extract their nutrients and antioxidants.
10 Teas That Speed Up Weight Loss
Different varieties of tea aids in weight loss. Their mode of action are similar in some cases while different in others.
1. Green Tea- The Popular Weight Loss Tea
Green tea is unfermented variety of tea containing about 250–350 mg tea solids, of which 30–42% are catechins and 3–6% caffeine.
The catechins are of 4 types - epigallocatechin-3-gallate (EGCG), epigallocatechin (EGC), epicatechin-3-gallate (ECG) and epicatechin (EC).
It also has flavonoids like quercetin, kaempferol and myricitin.
Green tea consumption aids in weight loss
A collection of data from 14 randomized control trials shows green tea consumption causes weight loss by affecting body weight, BMI, hipline, waistline and hip-waist ratio.
12 weeks of tea consumption leads to a 0.2-3.5 kg more weight loss than the control group. It reduces 5-10% of body fat and lowers the risk of cardiovascular diseases.
Green tea is a source of catechin which aids in weight loss. However, it doesn’t have a significant effect on weight maintenance after the intervention period.
Habitual drinking of tea reduces body fat. A study illustrated this effect.
A habitual drinking of tea for 10 years reduces 19.6% of body fat and 2.1% of waist-hip ratio than non-habitual drinking.
The relative level of catechin present in green tea effects weight loss.
A 12 week study with 583mg catechin and 96mg catechin per day showed a greater reduction of body fat, blood pressure cholesterol in the former group than the later.
This led to a reduced risk of cardiovascular diseases.
Green tea aids in weight loss by changing the gut microbiota.
It changes the ratio of firmicutes and bacteroidetes, thus making way for a more healthy gut.
These lead to a change in body fat composition, fat adsorption, resting energy expenditure.
The decreased body fat distribution is observed by the change in waist circumference and waist-hip ratio, changes in BMI, body fat percentage. (Read Green Tea For Weight Loss)
What does this mean? Green tea aids in weight loss by stimulating fat loss, improving metabolic and gut health. The polyphenols and high caffeine content of green tea is responsible for this.
Green tea boosts metabolism
Green tea enhances fat adsorption and thermogenesis (conversion of fat to heat energy required for body temperature).
It does this by inhibiting certain fat metabolism enzymes like catechol-O-methyltransferase, acetyl-CoA carboxylase, fatty acid synthase.
The caffeine and catechin polyphenols levels in green tea increases 24hour heat expenditure and fat oxidation level in humans.
This effect is due to activation of thermogenesis and fat oxidation. Both these controls body fat composition.
What does this mean? Green tea stimulates metabolism and breaks down accumulated fat.
Green tea effects gene expression in obese people
Green tea consumption effects adipogenesis (fat cell growth and division). It lowers adipogenesis-induced lipid accumulation in 3T3-L1 preadipocytes.
This is due to the blocking of transcription factors like C/EBPα and PPARγ in these cells.
Transcription factors are proteins which initiate the formation of other essential proteins.
Thus resulting in inhibition of fat cell growth.
Epigallocatechin-3-gallate is a polyphenol present in green tea.
This chemical compound reduces body weight by regulation the expression of various genes involved in fat metabolism. It lowers adipose tissue mass and ameliorates lipid profile.
What does this mean? The polyphenols in green tea regulates body weight by controlling the balance between genes required for adipogenesis (fat cell formation), lipolysis (break down of lipid) and thermogenesis.
Green tea consumption improves metabolic health
A year-long clinical study on Japanese workers showed a reduced blood cholesterol level for consumption of 10cups of tea per day.
Daily consumption of 1 cup of green tea leads to a significant reduction in cholesterol.
A meta-analysis of 14 randomized controlled trial showed 2.19 mg/dL reduction of Low-density lipoprotein cholesterol and total cholesterol by7.20 mg/dL .
A 5-year duration clinical study reported the effect of green tea consumption on type 2 diabetes risk.
Consumption of 6-3 cups of green tea per day causes 0.67 more reduction in risk of type 2 diabetes than the 1 cup per day consumption.
Thus green tea intake is inversely related to type 2 diabetes risk and hence reduces its prevalence.
What does this mean? Green tea reduces the total cholesterol level of blood by lowering the amount of LDL cholesterol (bad cholesterol). Thus it effects the lipid profile of obese people. Regular intake of green tea controls blood glucose level and prevents type 2 diabetes.
2. Black tea- The Most Common Tea In The Market
Black is the fully fermented and oxidized version of tea. It is made by exposing the tea leaves to air turning them blackish brown.
It has a strong flavor and taste.
Regular intake of black tea blocks pancreatic lipase activity. It suppresses the level of blood triglycerides. Black tea extract prevents weight gain.
Consumption of black tea blocks pancrease lipase activity.
This results in reduced absorption of fats from the intestine and reduces calorie absorption.
What does this mean? Black tea consumption prevents obesity by suppressing weight gain and fat absorption.
3. Mate tea- The Goodness of Coffee, Tea & Chocolate
Unlike other tea, yerba mate tea comes from the plant Ilex paraguariensis. It is prepared by drying the leaves and twigs.
It is most prevalent in South America.
They are rich in caffeine and xanthene alkaloids.
Daily intake of mate tea extract favours weight loss and weight management
A clinical study shows consumption of 3gm of mate tea extract daily (for 12 weeks) lowers body fat percentage, body fat mass and waist-hip ratio.
Yerba mate extract lowers lipid accumulation in cells and reduces the differentiation of fat cells.
This leads reduced weight gain. (Read 6 Benefits Of Yerba Mate For Weight Loss)
What does this mean? This articulates mate extract has a substantial role in weight loss and weight management and this is visible in the reduced body fat percentage, waist-hip ratio.
Mate tea extract helps in maintaining healthy blood glucose and cholesterol level
12 weeks daily 50-100g consumption of mate tea extract lead a decrease of total cholesterol by 9.49%, LDL- Cholesterol by 11.95% and HDL- cholesterol by 3.34%.
Consumption of mate tea restores the normal blood glucose level, serum cholesterol level and level of HDL, LDL and triglycerides.
Intake of 330 mL of roasted mate tea extract thrice daily lead to decrease in fasting blood glucose level, LDL and HDL cholesterol level, thus, enhancing the lipid profile and glycemic level in type 2 patients.
It also has a role in preventing DNA oxidation and lipid peroxidation. The anti-oxidant property comes to rescue in this process. This prevents cardiovascular diseases.
What does this mean? Mate tea extract controls the normal blood cholesterol and blood glucose level by regulating various proteins.
4.Oolong tea- The Most Complex Tea To Produce
Oolong tea is a partially oxidized or fermented form of tea. It comes from the same plant as green tea and black tea.
They have the same constituents but vary in their fermentation.
It is oxidized under the sun until the leaves curl and become twisted. The level of oxidation achieved is 8-85%.
Daily intake of oolong promotes weight loss
Consumption of 8gm of oolong tea for 6 weeks leads to a decrease in body fat content and lowered body weight.
The decrease of body weight and subcutaneous fat was more in women than in men.
It inhibits pancreatic lipase activity and enhances lipolysis or fat break down. This results in weight loss. (Read 5 Scientific Reasons-Why Oolong Tea Is Good For Weight Loss)
What does this mean? Oolong tea consumption causes weight loss due to lower fat content.
Oolong tea consumption decreases cholesterol level
600ml or more oolong tea consumption daily decreases total cholesterol level by 3.22 %, triacylglyceride by 11.99% and LDL-cholesterol by 6.69%.
This lowers the risk of dyslipidemia ( high levels of lipid blood).
What does this mean? Oolong tea decreases cholesterol level by lowering the LDL cholesterol and total cholesterol content.
5.Chamomile tea
Chamomile is a herb belonging to the daisy group. These floral heads are dried and used as an infusion tea.
There are 2 types of it- german and roman, of which only the former is used as a tea.
Chamomile tea consumption effects glycemic and lipid profile in overweight people
Chamomile has anti-inflammatory activity. It inhibits cyclooxygenase 2 (COX-2) and prevents inflammation. We know inflammation is major aspect of obesity.
An animal model shows it has potent anti-inflammatory and cholesterol-lowering activity.
Chamomile intake for 6 weeks reduces insulin resistance, glucose intolerance, plasma triacylglycerol, non-esterified fatty acids level.
It activates the expression of PPARγ gene. This gene is responsible for insulin resistance and other metabolic syndromes.
Consumption of 3gm of chamomile tea per 150ml of water, thrice a day for 8weeks decreases serum insulin level and glycosylated hemoglobin levels in type 2 diabetes people.
Another study highlights the cholesterol-lowering effect of chamomile. It significantly reduces total cholesterol level, LDL and triglyceride level.
What does this mean? Chamomile aids in weight loss due to its anti-inflammatory role. Its principal role lies in controlling secondary effects of obesity such as cholesterol and glucose level of blood.
6. Rooibos Tea -The Caffeine free Weight Loss Tea
Rooibos is a legume found in South Africa. The leaves of these plants are dried and used as herbal tea. This oxidation turns the leaves reddish in colour hence the name red bush tea.
Unlike conventional varieties, rooibos doesn’t contain caffeine. It constitutes of polyphenols including flavonoids, benzoic acid and high level of ascorbic acid.
Dietary intake of rooibos tea promotes weight loss and reduces cholesterol
Rooibos influences adipocyte differentiation.
It prevents the accumulation of fat. It lowers the expression of certain genes like PPARγ, PPARα, SREBF1 which are essential for fat cell development.
Rooibos reduces serum cholesterol level, fatty acid concentrations and triglycerides concentrations in the blood. It also reduces the size and number of adipocytes.
This due to the activation of AMP-activated protein kinase (AMPK) and the subsequent regulation of cellular energy homeostasis (maintaining the balance between external and internal energy level).
What does this mean? Roobibos tea consumption causes weight loss by preventing fat cell division, fat accumulation and fat metabolism.
7. White tea-The Most Delicate Tea
White tea is a minimally fermented tea, coming from the leaves and buds of Camellia sinesis. They are dried to inactivate the polyphenol oxidase enzyme.
There are white silvery threads over the buds which lead to the name white tea. It contains similar chemical compounds like black and green tea.
White tea extract prevents adipogenesis (fat cell development) by lowering the gene expression of factors like PPARγ, ADD1/SREBP-1c, C/EBPα.
What does this mean? White tea aids in weight loss by preventing fat cell growth and division.
8. Hibiscus tea- The Deep Crimson Tea
Hibiscus is a type of infusion tea made from the sepals of hibiscus flowers. It has vitamin C, mierals, citric acid, flavonoids, and polysaccharides. It has a cranberry-like flavour.
Hibiscus also acts in a similar mechanism and blocks PPARγ, C/EBPα expression resulting in inhibiting adipogenesis (fat cell development).
It also prevents fat accumulation.
It inhibits fat cell development by blocking MAPK and PI3-K pathway. These metabolic pathways play a crucial role in fat cell division.
What does this mean? Hibiscus tea prevents fat accumulation by regulating genes involved in fat cell growth.
9. Kola nut tea-The Caffeine Kick
Kola nut is 2% caffeine content fruit from kola nut trees found in western Africa. It has a bitter taste. Dried pods from this fruit are used for making infusion herbal tea, known as kola nut tea.
Kola nut reduces body weight and body fat percentage. It also improves the lipid profile by decreasing the bad cholesterol (LDL) and increasing the good cholesterol (HDL). Chronic consumption of it leads to reduced body weight and food intake.
However, due to its high caffeine content, moderate consumption is advised because excess caffeine can cause side effects such as nausea, vomiting, headaches, anxiety, palpitations.
What does this mean? Kola nut tea aid in weight loss by improving the lipid profile and reduces the overall percentage of body fat.
10.Fennel & Fenugreek tea-The Herbal Tea
Fennel is a herb used as a spice in Asian countries. It is rich in volatile oil compounds like anethole, fenchone and estragole.
These have anti-bacterial and anti-inflammatory property. Dries and crushed fennel seeds are used for making fennel tea.
Fenugreek in another popular herbal spice used in Asia.
They act as a body cleanser and detoxifier. Crushed and dried seeds of fenugreek are used for making fenugreek tea.
A clinical study compared the effect of fennel and fenugreek tea on weight loss.
Both of them had a positive impact on appetite by reducing hunger and increasing the fullness effect. Fenugreek tea had a greater impact than fennel tea.
What does this mean? Fennel and fenugreek tea aids in weight loss by controlling the appetite.
Which is the Best for Weight Loss?
A study compared the effect of green tea, black tea and oolong tea polyphenols on weight loss.
It was seen green tea had a significant impact on decreased food intake than others. All of them equally caused weight loss.
An ongoing phase 3 trial suggests yerba mate tea has a greater anti-oxidant property than green tea. Thus it may have greater cardio-protective ability than green tea.
Another study illustrates oolong tea has greater triglyceride reducing capacity than black and green tea whereas green tea is more effective in lowering total cholesterol level than the other two.
This study suggests fully fermented black tea and partially fermented oolong tea consumption is better than non-fermented green tea for enhancing the lipid profile.
Another study highlights the effect of green tea and sour tea (hibiscus)tea on glucose level in type 2 diabetes patients. Green tea was found better in this aspect.
What does this mean? Considering all aspects (weight loss, lipid profile and glucose level) green tea and oolong tea are the ideal drinks for weight loss.
Nutritional Value and Health Bbenefits of Tea
Tea is a healthy nutritious beverage offering a range of health benefits.
Tea is anti-oxidant by nature due to the presence of flavonoids. Hence it reduces oxidative stress in the body.
Tea lowers cholesterol level of blood. It lowers LDL cholesterol or bad cholesterol and the total cholesterol content.
Tea is anti-carcinogenic. It prevents different types of cancer like stomach cancer, colon cancer, lung cancer, breast cancer etc.
The polyphenols present in tea are responsible. Green tea is the most effective in this regard.
Oolong tea extract have anti-caries property. The antibacterial property of polyphenols is responsible for this. Green tea and black tea also has this property
Consumption of tea leads to high bone mineral density in women. This is due to the fluoride content and the polyphenols aiding in bone resorption
Intake of high quantity of fluids like tea prevents kidney stones. Hence, it plays a role in preventing kidney stones
How Much Tea to Consume For Weight Loss?
The prescribed amount of tea consumption varies according to the variety of tea and their effect.
For green tea the advised limit is 1-3g a day , for mate tea it is 3gm per day (1gm in each meal- thrice a day)and for oolong tea it is 8gm/day.
Thus, in accordance with the variance, it would be prudent to indulge in 2-3 cups daily.
Precautions
Although there aren’t any side effects of drinking tea there are few things you should consider:
Be vigilant while buying your tea. Check the sugar content and stay away from sweetened versions.
Refrain from adding extra sugar or sweetening supplements or carbonated compounds.
The caffeine in tea has potential side effects when taken in excess. More than 500-600mg of caffeine per day affects the nervous system. It can lead to insomnia, faster heartbeat, muscle tremors and stomach problems.
More than 3cups of black tea per day is not advised during breastfeeding.
High dosage of black tea can cause anxiety disorders, anemia, heart problems, diabetes, seizures and glaucoma.
Green tea consumption has mild to severe side effects when consumed in excess. The mild side effects include diarrhea, stomach upset etc.
Severe implications include allergies and swellings, irregular heartbeat mood swings. Certain medications like the blood thinner warfarin react with it.
Chamomile can cause uterine contractions leading to miscarriage. It should be avoided during pregnancy.
It can cross-react with drugs containing apigenin. These are natural anti-coagulant or non-steroidal anti-inflammatory drugs.
High dosage of yerba mate tea can cause cancer in the mouth and throat, increase the blood pressure and heart rate. It increases the risk of liver diseases.
Rooibos can have a drug interaction with chemotherapy drugs.
All these side effects are only a result of excessive consumption of tea. If on any medications, please do consult a doctor to rule out drug interactions.
Conclusion
Tea is a rich source of antioxidants, nutrients and various anti-obesity agents.
It is definitely no wonder drug for weight loss but it can promote weight loss induced by exercise and dietary changes.
Also, teas are of great help in combating abdominal obesity and serve as a good detox.
So those were the 10 types of tea that are scientifically proven to induce weight loss.