Green tea has been shown to cause weight loss by increasing metabolism and fat breakdown as well as decreasing the digestion and absorption of fats in our stomachs and intestines. It has also been shown to prevent pre-fat cells from becoming fat cells!
Despite our current population being in the rising peak of the obesity epidemic, no one is promoting daily green tea for weight control. Rather, diet soda has become a mainstream drink in our society. This is the result of clever marketing from large corporate soda industries with lots of money involved at the unfortunate cost of our health (but more on this in another discussion!)
So, how well does green tea actually work for weight loss? The study we go through below looked at its effect with or without exercise and the results are astonishing!
The Green Tea Study
In a randomised, double-blinded and placebo-controlled trial, a group of overweight women were divided into 4 groups with the following variables:
- Group 1 – Green tea (10g of powder mixed into a drink, twice-a-day)
- Group 2 – Placebo
- Group 3 – Green tea + Resistance training program 3x/week
- Group 4 – Placebo + Resistance training program 3x/week
Each participant received a low calorie diet of 1200 calories per day for 4 weeks to cause weight loss before they were split into their respective groups. The goal of this was to metabolically adapt the participants. This one-month period is where most people would lose weight before stabilising or gaining weight (don’t we all know that feeling…) because their bodies have decreased their metabolisms and are preferentially storing fats.
Why did the researchers do this? They did this so they could better see the effect of green tea. Any weight loss occurring after the stabilisation period is more likely associated to green tea consumption.
The participants were then split into their groups with variables as above. Their baselines were measured and then the study continued for 8 weeks with the same diet but with the variables applied.
Numerous measurements were recorded at baseline and at the conclusion of the study to assess the effects of green tea. These included:
- Resting Metabolic Rate (RMR)
- Weight, Waist Circumference (WC), BMI, Body Fat Mass & Percentage, Lean Body Mass (Muscle)
- Strength – One Rep Maximum (1RM) – for Group 3 & 4
- Blood tests: Sugar and insulin levels, cholesterol/lipid levels, kidney function and general inflammation levels
The Power of Green Tea
At the end of the study, the findings for the Green Tea group were incredible!
Here is a summary of some of the key findings on average:
Group 1: Green tea
- Lost 5.7 kg / 12.6 lbs in body weight
- Lost 4kg / 8.8 lbs in body fat mass
- Gained 1.2kg in lean body mass (muscle)
- Reduced their body fat percentage by 4.7%
- Reduced their waist circumference by 5.8 cm / 2.3 inches
Group 2: Placebo
- Remained the same in body weight
- Gained 2.1 kg / 4.6 lbs in body fat mass
- Lost 2.3 kg / 5.1 lbs in lean body mass
- Increased their body fat percentage by 2.1%
- Increased their waist circumference by 1.9 cm / 0.4 inches
Comparing the two no-exercise group, we can see that the Green Tea group was able to lose significant body weight whilst maintaining their lean body mass. This means that mostly body fat was stripped off (~4 kilograms of it in this case!). This could imply that green tea stimulates increased fat burning with lean muscle preservation despite our bodies’ adaptations to a low calorie diet (muscle breakdown for energy and increased fat storage).
The Placebo group, on the other hand, remained about the same in body weight despite a low caloric diet. They also gained body fat, likely because the low calorie diet triggered their bodies to store it. Their lean body mass also suffered as their bodies broke down muscle to use as energy.
A 1200 calorie diet will leave most people feeling hungry more often than not. Whilst we do not at all encourage a restrictive and low calorie diet, if we happened to be on one for weight loss, we would definitely prefer to have green tea on our sides so that our efforts are rewarded!
Now, let’s see how the resistance training groups fared:
Group 3 (Green tea + Resistance training)
- Gained 1.4 kg in body weight
- Lost 9.7kg / 21.4 lbs in body fat mass
- Gained 6.6 kg / 14.6 lbs in lean body mass
- Reduced their body fat percentage by 10.3%
- Reduced their waist circumference by 9.2 cm / 3.6 inches
Group 4 (Placebo + Resistance training)
- Remained the same in body weight
- Lost 3.2 kg / 7.1 lbs in body fat mass
- Lost 3.5 kg / 7.7 lbs in lean body mass
- Decreased their body fat percentage by 4.4%
- Reduced their waist circumference by 2.4 cm / 0.9 inches
The Green Tea group actually gained weight but not in the way one might think! They lost an abundant amount of body fat whilst also building a significant amount of lean muscle tissue from their training. Overall, this reduced their body fat 10% – an extraordinary reduction in such a time frame. Interestingly, the drop in body fat mass, body fat percentage and waist circumference was actually greater than all three groups combined.
Additionally, despite the low calorie diet which generally does not promote muscle growth, the Green tea group was able to grow almost twice the amount of lean body mass compared to Placebo. We don’t know if green tea has lean muscle building or protective properties and investigating this is beyond the scope of this article. It would appear from the results of this trial that it certainly may!
In terms of strength testing, both groups were tested by using the a leg press, bench press and back pull down machines and instructed to perform a 1RM. Both groups showed significant improvements with the Green Tea group showing more so. Respectively, the Green Tea group improved their leg press, bench press and pull down by 7.2%, 4.8% and 5.5% more than the Placebo group did. We think that the result is probably due the higher lean muscle growth that occurred in the green tea group, however it is not possible to conclude without further studies.
Green tea is associated with a host of health and wellness benefits which we will discuss in another article in future. For weight loss and maintenance, it would appear to be a winner!
The study used 10g of green tea powder twice-a-day. We personally do not prefer measuring our green tea intake this way so we simply found a number of ways we could implement green tea into our daily lives.
To ensure we get our daily dose, we have use a range of strategies:
- We use green tea powder or matcha powder instead of tea bags to ensure higher concentrations of green tea
- We almost always have hot pot of green tea available while working at our desks (we always fight over who has to brew the next pot…)
- We add matcha or green tea powder to smoothies, oatmeals and nourish bowls.
- We have matcha lattes and matcha-based desserts maybe a little too frequently!
Let us know how you like to have your green tea or matcha, we would love some more ideas!
Keep In Mind
As always, we should keep in mind that a whole food plant-based lifestyle with regular exercise and mindfulness is the first priority in achieving our health and wellness goals. Adding or excluding specific foods may help us achieve our goals sooner but they should not be the focus of our approach!
- Cardoso GA, Salgado JM, Cesar Mde C, Donado-Pestana CM. The effects of green tea consumption and resistance training on body composition and resting metabolic rate in overweight or obese women. J Med Food. 2013;16(2):120-127. https://pubmed.ncbi.nlm.nih.gov/23140132/