Green Tea Weight Loss Miracle: Truth or Hype?

by Evelyn Reid

Jun 28, 2017 | Tea of the Week

Could it really be that simple? Drink X amount of green tea a day and watch fat effortlessly melt off your midriff? Effortlessly might be pushing it a bit, but select studies have shown a higher calorie burn in research subjects consuming green tea.

Green Tea: Feel the Burn

In the case of a 2008 Thai study [1], participants in the green tea group burned about 89 calories more a day… doing absolutely nothing. But when you think of it, that 89 calories is barely a single serving of cheese and it took them 8 weeks of ingesting three 250mg capsules of green tea extract a day to get to that burn point. But it’s something. Whether that moderately low resting energy expenditure increase would have persisted beyond the 12 weeks they were being studied is anyone’s guess.

And that’s part of the problem. We’re still guessing.

Browse through the results of a couple dozen other research projects on the subject, and it’s clear green tea is doing something when it comes to fat loss. But to what extent?

Read Also: Why Tea?
And: Could Listening to Your Heart Make You a Mind-Reader? Science Closer to Saying Yes

“Browse through the results of a couple dozen other research projects on the subject, and it’s clear green tea is doing something when it comes to fat loss. But to what extent?”

A Swiss study from 1999 [2] showed a similar effect to the Thai study, with experimental group subjects taking green tea extract expending, when averaged out, an extra 79 calories over the course of 24 hours. That’s like skipping rope for 8 minutes. Ah, but could it be the caffeine that’s increasing resting energy expenditure? Researchers wondered the same thing, so they had another group ingest the same amount of caffeine as the green tea group. Verdict? The group who only ingested caffeine failed to show the kind of increases in energy expenditure and fat oxidation the green tea group experienced thus green tea, again, appears to be doing something.

So if micronutrients in green tea are acting synergistically with the tea’s naturally-occurring caffeine content to burn more calories and fat than caffeine could ever do in other beverages, does that mean we should load our green tea with an extra shot of caffeine?

Not so fast. One 2005 Dutch study [3] noticed subjects taking a green tea mixture continued to lose weight during a three-month observation period, but only if they had a tendency to consume less than 300mg of caffeine a day. Subjects with a high caffeine profile—people who consumed more than 300mg of caffeine a day, the rough equivalent of 2 cups of coffee or more—who also took green tea extract ended up gaining weight during the same three-month observation period, even though they lost a smidgeon more during the four-week diet.

In case you’re wondering, one cup of green tea naturally contains more or less 30mg of caffeine. At that rate, you’d have to drink 5 cups of green tea to catch up with the caffeine in one single cup of coffee. If this study is on to something, then we might need to quit coffee altogether if there’s any hope of keeping our fat-burning engines revved up by green tea over the long term.

Green Tea Leads to Weight Loss… and Weight Gain?

To get to the bottom of these conflicting results, researchers conducted meta-analyses [4, 5, 6] comparing different green tea weight loss studies carried out over the last 15 years or so and of them? The most dramatic difference in weight loss was observed in a 2005 Japanese study [7]. The experimental group taking green tea extract lost on average 7.7 pounds more over a 12-week period than the control group who didn’t ingest any green tea. Other Japanese studies on the same subject have for the most part produced positive, if less pronounced, weight loss results.

“So all we know at this point is that we need a lot more data before concluding that green tea has anything other than a minor effect on fat oxidation and resting energy expenditure. In other words, consuming green tea to melt the pounds away is, to the best of our knowledge, slightly more effective than wishful thinking.”

But what’s odd though is, generally speaking, studies carried out in other parts of the world involving subjects ingesting sometimes more green tea extract than in that infamous 2005 Japanese study showed participants actually lost less weight in a comparable time period. So even though some studies had its subjects consuming more green tea than the 7.7 pound weight loss group in Japan, they didn’t lose as much weight.

Was there something about the diet of the people in that 2005 Japanese study that interacted with the green tea to cause a greater weight loss? Could it be the Western tendency to consume more caffeine than in Japan interfering with green tea’s alleged weight loss effects? Was it something else?

And how’s this for a mind boggle? In one 2007 Australian study [8], the green tea group actually gained weight and a minute amount of body fat compared to the control group who lost a wee bit of weight and body fat. Go figure. The difference was subtle and scientifically insignificant, however.

All in all, the most experimentally robust studies failed to report any major weight loss, if any significant weight loss differences between green tea groups and placebo groups were recorded at all. Even the Thai study mentioned earlier in this post which found its green tea group burning more calories a day calculated that green tea subjects lost 1.54 pounds more than the placebo group… a measly 1.54 extra pounds over the course of 12 weeks! You’ll get the same results from eating 9 fewer almonds a day.

It should be noted that analyzing these studies side by side is less than obvious. While participants within the same study were typically on the same diet, it’s not the case across different studies, nor was the same brand of green tea extract consumed across every study. Green tea extract quality and amount per capsule vary tremendously by brand making that a problem.

There are also other concerns not elaborated herein—caffeine tolerance, racial differences, geographical lifestyle differences, exercise parameters not matching across studies—which may be affecting results, all lengthy subjects on their own.

So all we know at this point is that we need a lot more data before concluding that green tea has anything other than a minor effect on fat oxidation and resting energy expenditure. In other words, consuming green tea to melt the pounds away is, to the best of our knowledge, slightly more effective than wishful thinking.

Beware News Reports on Green Tea

Seriously folks. The misinformation is real. Don’t fall for those news reports about the latest miracle study. Reporters writing up those articles generally have no science background and frankly, don’t know how to analyze experimental design. Even when the odd journalist does have a background in science and has trained in a research environment, they generally don’t have time to put the latest results into a greater context and/or are under extreme pressure to exaggerate the results to produce clickbait headlines and ledes that attract the eyeballs their news outlets need to stay in business. The news cycle is what it is. And it drives science crazy.

Does Green Tea EVER Lead to Weight Loss?

But you know what? There’s a brilliant silver lining to all of this. There is one way you can make green tea work for you and without going on a diet. Replacing juice, energy drinks, and sugary soda pop with green tea while keeping everything else in your lifestyle the same can have a dramatic effect on weight loss. The average can of cola, for example, has 150 calories. The average cup of green tea? Or any kind of loose leaf tea for that matter? Maybe 2 calories. Replace that one can of soda a day with green tea changing nothing else in your diet and lifestyle and you’ll possibly lose over 15 pounds in a year. Substitute a two-soft-drinks-a-day habit with tea and you might effortlessly drop 30 pounds in a year. Can’t live without 3 cans of soda a day? Try. Drop the trio of pop and you could lose up to 45 pounds by this time next year.

Too painful without the sugar? I hear ya. I’ve been there. There was a time when asking me to cut sugar—or honey, or glorious Canadian maple syrup—out of my liquids was like requesting I drink toilet water. I used to down a minimum of two litres of juice a day as a teen. Is it any wonder I was on the cusp of obesity?

Part of my life-changing solution was removing all hints of juice and its empty calories from my life and swapping the sugar in my coffee and tea with stevia. It was hard at first because most of the stevia I found had this wonky, bitter aftertaste. But I eventually discovered brands that managed to get rid of or at least minimize that off-putting flavor. The only two stevia brands I can stomach are NOW and Herbal Select, irreplaceable game changers in my goal to eliminate added sugar in my liquids and even some of my baked goods.

Still need your sugar? Again, I get it. My coffee of yore contained three heaping teaspoons. Today? Nada. And it was a fairly painless process involving baby steps. Look at it this way. If one can of cola has about 10 teaspoons of sugar, then removing that soft drink from your diet and replacing it with one or two teaspoons per cup of tea is already a major improvement.

And the great part is your taste buds gradually adjust to the shift in sugar ingestion. Before you know it, you won’t want as much sugar in your drinks. It’ll just come naturally. I’ve reached the point where not only have I cut sugar out of tea, but I’ve reduced the stevia in my tea by two-thirds and even then only using it on occasion instead of as a rule. My taste gradually changed without making any effort. It just kinda happened.

Take it slow and you’ll get there too.

References

  1. Auvichayapat P, Prapochanung M, Tunkamnerdthai O, Sripanidkulchai B, Auvichayapat N, Thinkhamrop B et al. Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial. Physiol Behav 2008; 93 (3): 486-91.
  2. Dulloo AG, Duret C, Rohrer D, Girardier L, Mensi N, Fathi M et al. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutr 1999; 70 (6): 1040-5.
  3. Westerterp-Plantenga MS, Lejeune MPGM, Kovacs, EMR. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obesity Research 2005; 13: 1195–1204.
  4. Baladia E, Basulto J, Manera M, Martínez R, Calbet D. Efecto del consumo de té verde o extractos de té verde en el peso y en la composición corporal; revisión sistemática y metaanálisis. Nutr Hosp 2014; 29(3): 479-90.
  5. Jurgens TM, Whelan AM, Killian L, et al. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database Syst Rev 2012; 12: CD008650.
  6. Hursel R, Viechtbauer W, Westerterp-Plantenga MS, The effects of green tea on weight loss and weight maintenance: A Meta-analysis. International Journal of Obesity 2009; 33: 956–961
  7. Kozuma K, Chikama A, Hishino E, Kataoka K, Mori K, Hase T, et al. Effect of intake of a beverage containing 540mg catechins on the body composition of obese women and men. Progress in Medicine 2005; 25: 185–97.
  8. Hill AM, Coates AM, Buckley JD, Ross R, Thielecke F, Howe PRC. Can EGCG reduce abdominal fat in obese subjects? Journal of the American College of Nutrition 2007; 26(4): 396S–402S.

Green Tea Weight Loss Miracle: Truth or Hype?

by Evelyn Reid

Jun 28, 2017 | Tea of the Week

Could it really be that simple? Drink X amount of green tea a day and watch fat effortlessly melt off your midriff? Effortlessly might be pushing it a bit, but select studies have shown a higher calorie burn in research subjects consuming green tea.

Green Tea: Feel the Burn

In the case of a 2008 Thai study [1], participants in the green tea group were expending about 89 calories more a day… doing absolutely nothing. Thing is that 89 calories is barely a single serving of cheese and it took them 8 weeks of ingesting three 250mg capsules of green tea extract a day to get to that point. But it’s something. Whether that moderately low resting energy expenditure increase would have persisted beyond the 12 weeks they were being studied is anyone’s guess.

And that’s part of the problem. We’re still guessing.

Browse through the results of a couple dozen other research projects on the subject, and it’s clear green tea is doing something when it comes to fat loss. But to what extent?

Read Also: Why Tea?
And: Could Listening to Your Heart Make You a Mind-Reader? Science Closer to Saying Yes

A Swiss study from 1999 [2] showed a similar effect to the Thai study, with experimental group subjects taking green tea extract burning, when averaged out, an extra 79 calories over the course of 24 hours. That’s like skipping rope for 8 minutes. Ah, but could it be the caffeine that’s increasing resting energy expenditure? Researchers wondered the same thing, so they had another group ingest the same amount of caffeine as the green tea group. Verdict? The group who only ingested caffeine failed to show the kind of increases in energy expenditure and fat oxidation the green tea group experienced so green tea, again, appears to be doing something.

So if green tea is acting synergistically with its naturally-occurring caffeine content to burn more calories and fat than caffeine could ever do in other beverages, does that mean we should load our green tea with an extra shot of caffeine?

Not so fast. One 2005 Dutch study [3] noticed subjects taking a green tea mixture continued to lose weight during a three-month observation period, but only if they had a tendency to consume less than 300mg of caffeine a day. Subjects with a high caffeine profile –people who consumed more than 300mg of caffeine a day, the rough equivalent of 2 cups of coffee or more– who also took green tea extract ended up gaining weight during the same observation period.

In case you’re wondering, one cup of green tea naturally contains more or less 30mg of caffeine. At that rate, you’d have to drink 5 cups of green tea to catch up with the caffeine in one single cup of coffee. So if that Dutch study is onto something, then we might need to quit coffee altogether if there’s any hope of keeping our fat-burning engines revved up by green tea over the long term.

Green Tea Leads to Weight Loss… and Weight Gain?

To get to the bottom of these conflicting results, researchers conducted meta-analyses [4, 5, 6] comparing different green tea weight loss studies carried out over the last 15 years or so and of them? The most dramatic difference in weight loss was observed in a 2005 Japanese study [7]. The experimental group taking green tea extract lost on average 7.7 pounds more over a 12-week period than the control group who didn’t ingest any green tea. Other Japanese studies on the same subject have for the most part produced positive, if less pronounced, weight loss results.

But what’s odd though is, generally speaking, studies carried out in other parts of the world involving subjects ingesting sometimes more green tea extract than in that infamous 2005 Japanese study showed participants actually lost less weight in a comparable time period. So even though some studies had its subjects consuming more green tea than the 7.7 pound weight loss group in Japan, they didn’t lose as much weight.

Was there something about the diet of the people in that 2005 Japanese study that interacted with the green tea to cause a greater weight loss? Could it be the Western tendency to consume more caffeine than in Japan interfering with green tea’s alleged weight loss effects? Was it something else?

And how’s this for a mind boggle? In one 2007 Australian study [8], the green tea group actually gained weight and a minute amount of body fat compared to the control group who lost a wee bit of weight and body fat. Go figure. The difference was subtle and scientifically insignificant, however.

All in all, the most experimentally robust studies failed to report any major weight loss, if any significant weight loss differences between green tea groups and placebo groups were recorded at all. Even the Thai study mentioned earlier in this post which found its green tea group burning more calories a day calculated that green tea subjects lost 1.54 pounds more than the placebo group… a measly 1.54 extra pounds over the course of 12 weeks! You’ll get the same results from eating 9 fewer almonds a day.

It should be noted that analyzing these studies side by side is less than obvious. While participants within the same study were typically on the same diet, it’s not the case across different studies, nor was the same brand of green tea extract consumed across every study. Green tea extract quality and amount per capsule vary tremendously by brand making that a problem.

There are also other concerns not elaborated herein—caffeine tolerance, racial differences, geographical lifestyle differences, exercise parameters not matching across studies—which may be affecting results, all lengthy subjects on their own.

So all we know at this point is that we need a lot more data before concluding that green tea has anything other than a minor effect on fat oxidation and resting energy expenditure. In other words, consuming green tea to melt the pounds away is, to the best of our knowledge, slightly more effective than wishful thinking.

“So all we know at this point is that we need a lot more data before we can conclude that green tea has anything other than a minor effect on fat oxidation and resting energy expenditure. In other words, consuming green tea to melt the pounds away is, to the best of our knowledge, slightly more effective than wishful thinking.”

Beware News Reports on Green Tea

Seriously folks. The misinformation is real. Don’t fall for those news reports about the latest miracle study. Reporters writing up those articles generally have no science background and frankly, don’t know how to analyze experimental design. Even when the odd journalist does have a background in science and has trained in a research environment, they generally don’t have time to put the latest results into a greater context and/or are under extreme pressure to exaggerate the results to produce clickbait headlines and ledes that attract the eyeballs their news outlets need to stay in business. The news cycle is what it is. And it drives science crazy.

Does Green Tea EVER Lead to Weight Loss?

But you know what? There’s a brilliant silver lining to all of this. There is one way you can make green tea work for you and without going on a diet. Replacing juice, energy drinks, and sugary soda pop with green tea while keeping everything else in your lifestyle the same can have a dramatic effect on weight loss. The average can of cola, for example, has 150 calories. The average cup of green tea? Or any kind of loose leaf tea for that matter? Maybe 2 calories. Replace that one can of soda a day with green tea changing nothing else in your diet and lifestyle and you’ll possibly lose over 15 pounds in a year. Substitute a two-soft-drinks-a-day habit with tea and you might just effortlessly drop 30 pounds in a year. Can’t live without 3 cans of soda a day? Try. Drop the trio of pop and you could lose up to 45 pounds by this time next year.

Too painful without the sugar? I hear ya. I’ve been there. There was a time when asking me to cut sugar—or honey, or glorious Canadian maple syrup—out of my liquids was like requesting I drink toilet water. I used to down a minimum of two litres of juice a day as a teen. Is it any wonder I was on the cusp of obesity?

Part of my life-changing solution was removing all hints of juice and its empty calories from my life and swapping the sugar in my coffee and tea with stevia. It was hard at first because most of the stevia I found had this wonky, bitter aftertaste. But I eventually discovered brands that managed to get rid of or at least minimize that off-putting flavor. The only two stevia brands I can stomach are NOW and Herbal Select, irreplaceable game changers in my goal to eliminate added sugar in my liquids and even some of my baked goods.

Still need your sugar? Again, I get it. My coffee of yore contained three heaping teaspoons. Today? Nada. And it was a fairly painless process involving baby steps. Look at it this way. If one can of cola has about 10 teaspoons of sugar, then removing that soft drink from your diet and replacing it with one or two teaspoons per cup of tea is already a major improvement.

And the great part is your taste buds gradually adjust to the shift in sugar ingestion. Before you know it, you won’t want as much sugar in your drinks. It’ll just come naturally. I’ve reached the point where not only have I cut sugar out of tea, but I’ve reduced the stevia in my tea by two-thirds and even then only using it on occasion instead of as a rule. My taste gradually changed without making any effort. It just kinda happened.

Take it slow and you’ll get there too.

References

  1. Auvichayapat P, Prapochanung M, Tunkamnerdthai O, Sripanidkulchai B, Auvichayapat N, Thinkhamrop B et al. Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial. Physiol Behav 2008; 93 (3): 486-91.
  2. Dulloo AG, Duret C, Rohrer D, Girardier L, Mensi N, Fathi M et al. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutr 1999; 70 (6): 1040-5.
  3. Westerterp-Plantenga MS, Lejeune MPGM, Kovacs, EMR. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obesity Research 2005; 13: 1195–1204.
  4. Baladia E, Basulto J, Manera M, Martínez R, Calbet D. Efecto del consumo de té verde o extractos de té verde en el peso y en la composición corporal; revisión sistemática y metaanálisis. Nutr Hosp 2014; 29(3): 479-90.
  5. Jurgens TM, Whelan AM, Killian L, et al. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database Syst Rev 2012; 12: CD008650.
  6. Hursel R, Viechtbauer W, Westerterp-Plantenga MS, The effects of green tea on weight loss and weight maintenance: A Meta-analysis. International Journal of Obesity 2009; 33: 956–961
  7. Kozuma K, Chikama A, Hishino E, Kataoka K, Mori K, Hase T, et al. Effect of intake of a beverage containing 540mg catechins on the body composition of obese women and men. Progress in Medicine 2005; 25: 185–97.
  8. Hill AM, Coates AM, Buckley JD, Ross R, Thielecke F, Howe PRC. Can EGCG reduce abdominal fat in obese subjects? Journal of the American College of Nutrition 2007; 26(4): 396S–402S.