Fasting with green tea

I've been playing around with brief (18-24 hour) fasts with the use of green tea. Of the several variations on fasting, such as juice "fasts,"  I've been most impressed with the green tea experience.

While the weight loss effects of daily green tea consumption are modest, there seems to be a specific satiety effect that has now been demonstrated in multiple studies, such as this and this. In other words, green tea, through an uncertain mechanism, reduces hunger. The effect is not just due to volume, since the effect cannot be reproduced with hot water alone.

I therefore wondered whether green tea might be a useful beverage to consume during a fast, as it might take the "edge" off of hunger. While hunger during a fast in the wheat-free is far less than wheat-consuming humans, there is indeed an occasional twinge of hunger felt.

So I tried it, brewing a fresh 6-8 oz cup evert two hours or so. I brewed a pot in the morning while at home, followed by brewing single cups using my tea infuser at the office. Whenever I began to experience a hunger pang, I brewed another cup and sipped it. I was pleasantly surprised that hunger was considerably reduced. I sailed through my last 18 hours, for instance, effortlessly. The process was actually quite pleasant.

I brew loose Chinese bancha, sencha, and chunmee teas and Japanese gyokuro tea. Gyokuro is my favorite, but also the most expensive. Bancha is more affordable and I've used that most frequently.

If anyone else gives this a try, please report back your experience.

Comments (34) -

  • Phyllis

    6/1/2011 12:04:50 AM |

    I would like to know if this works with iced green tea as well. I used a method of one meal per day to loose 50+ pounds. I found it pretty easy, all in all, but have regained about 20 now and need to get back on it. I think I will give iced green tea a try! (I'm not crazy about hot green tea, but like it fine iced)

  • preserve

    6/1/2011 12:09:56 AM |

    I use tea as a method of extending eating intervals.  It works well.  I'm sure a lot of it has to do with the "upper" effect.  Ie.  uppers reduce appetite as a result of blocked sensory.

    I find fasting and sensory blocking to be counter-productive.

  • Geoffrey Levens, L.Ac.

    6/1/2011 12:33:19 AM |

    May be other effects but caffeine and it's cousin theobromine in the tea are pretty reliable appetite suppressants.  But isn't getting jacked up (even if only a little) a bit counter productive to some of the potential benefits of fasting?  The idea is to rest your physiology while catabolism is in full swing. Activating the sympathetic nervous system so you don't have to experience the sensations you don't like during the early stages of fasting does not seem to me to really promote that.

  • fredt

    6/1/2011 1:09:29 AM |

    Yes, green tea reduces my hunger; I just use Tetley in the bag. Some of the greens do not have a satiating effect on me, nor do any of the black teas. Coffee increases hunger for me. Bullion cubes or OXO packets also help. I make a 1.5 l thermos, and suck on that until its done. Some days 3 or 4 of them in a day. I think I have more hunger than most people, but I am down 55 kgs, 2 to 4 years ago and have been down for 2 years.

    The other thing that helps me is chew-able Vitamin C, a couple of 500s any time I feel hungry. It seems to raise BG, possible due to BG sparing, as it is required for far oxidation, or inside cell far transport, depending on who is explaining. Two 500's raise my BG form 4.0 to 5.3 -- OK US 72 to 95.
    I am off wheat mostly; occasionally Clam chowder, sausages, and a few crackers for low BG issues. One cracker raises BG 1.5 at 15 mins.

    Thanks for the one hour BG idea. Some of my higher protein meals were a problem, like 280 Calories of canned salmon ran my BG to 9.0 (OK 162). And my doctor says I an not diabetic but my a.m. BG sure is erratic, 4.0 to 6.2 this week.

  • Sharon

    6/1/2011 2:22:06 AM |

    Hey Phyllis, I'm with you. I have been drinking 4 cups green tea made with tea bags and then chilled and have noticed that I'm not as hungry but didn't really connect it with the tea itself. I need to lose 50 lbs and I like the idea of one meal a day.

  • Scott P.

    6/1/2011 2:24:11 AM |

    Green tea, or any tea actually, makes me a little ill on an empty stomach.  Not sure but believe it is the tannins.  I also was consuming a lot of green/white tea while fasting and I just felt really acidic and my face got red splotches, which seems to coincide with acidity.  I know the net result is supposed to be alkaline for green/white tea but that has not been my experience.  Recently, I've been adding a tablespoon of apple cider vinager to a cup of warm water.  Went a fairly easy 18 hours today but did break down and had four or five macadamia nuts around 12 hours in.

  • MAS

    6/1/2011 2:44:37 AM |

    I absolutely drink green and lightly oxidized oolongs during my fasts.   It curbs the hunger and provides focus.  Been doing it for 2.5 years.

  • Dr. William Davis

    6/1/2011 2:49:43 AM |

    After millennia of human starvation, to think that we still have tons to learn about fasting used for health purposes!

    Phyllis--While I've not tried it personally, nor do I know of any formal data, I expect that iced green tea--provided it is real brewed green tea, and not the bottled variety--should work every bit as well.

  • Dianne - TPSW

    6/1/2011 1:28:40 PM |

    I am unable to drink green tea at all on an empty stomach, I will absolutely throw up if I do.  I end up with pullovertothesideoftheroadI'mgoingtopukeyesseriously!".   I actually threw up all over my suit once which was really special.  Green tea with food often makes me queasy as well.  I am allergic to oak so I think there may be a tannin connection as some heavy oak wines are problematic for me.

  • Anne

    6/1/2011 4:46:28 PM |

    I am making today a fast day. I have been drinking a mix of green and white tea but it is decaffeinated.  How often should one fast?

  • Jonathan Carey

    6/1/2011 5:58:30 PM |

    For those who get dizzy on green tea, try puerh tea.  It is a fermented green tea that is also much lower in caffeine and it taste much better than green.  It is the equivalent of drinking an aged red wine over 2 buck chuck.

  • JLL

    6/2/2011 11:27:49 AM |

    This question has been around for quite some time,  but no one seems to know the answer for certain.

    Theoretically at least, consuming antioxidants during fasting could be detrimental to autophagy (removing "junk" cells), since antioxidants might suppress the stress response from fasting. This is why some studies show antioxidants and exercise are a bad combination -- you *want* some stress to happen so that the body can adapt to it.

    Then again, there is the theory that small amounts of antioxidants actually work through the same mechanism as fasting and exercise -- hormesis. In which case fasting + antioxidants might complement each other. But that's just speculation.

    What we do know from studies is that green tea seems to increase weight loss, for example when combined with calorie restriction (and thus should apply to fasting):

    And when combined with exercise:

    And when combined with capsaicin (from chilli pepper), it reduces the feeling of hunger and thus calorie intake:

    So all in all, whatever the mechanism is, if you're fasting just for the sake of losing weight, I'd say green tea is a pretty good bet.

    - JLL

  • Paul Lee

    6/2/2011 12:21:31 PM |

    Would depend on the length of fasts, but the East Stop East method advocates two fasts per week.  My fasts are now usually shorter, as they kind of trained me to stop grazing. I usually don't bother with breakfast now. The more you eat, the more you want to eat sometimes.

  • nina

    6/2/2011 8:10:00 PM |

    I'm subscribed to your blog, but since  you changed format the posts haven't been showing up in my mail box.  I tried to re-subscribe, but am told I'm already subscribed.  How do I get back in the loop?


  • Dr. William Davis

    6/3/2011 1:31:00 AM |

    Anyone not receiving email versions of this blog:

    I wonder if the shift over to the new platform caused a few glitches. My blog IT help is out of commission temporarily. Therefore, please sign up again at the top.

    Sorry about that.

  • Dr. Mary Taylor, PT, DPT

    6/3/2011 6:41:41 PM |

    Yes, I completely agree with you! I went 90% wheat and sugar free from November 2010 to February 2011 and lost a whopping 2 pounds. It wasn't until I went to 95% or more wheat free that I was able to start losing weight. I am now 100% wheat free and I have lost 36.2 pounds in 15 weeks. I have also been able to significantly cut my caloric intake to 500-700 calories per day (sometimes less than 500) using iced jasmine green tea. I truly believe that a diet that is lower in calories is better for health. I typically drink 6-8 glasses a day and I really enjoy it. It helps immensely with any hunger I may have and completely satisfies my sense to eat. I use any of the varieties available in tea bag (Numi, Two Leaves and a Bud, Stash, and Mighty Leaf are my favorites). I typically choose whatever's on sale. I also drink a full glass every morning prior to eating and that also seems to stimulate my colon which is a bonus as well when consuming such low caloric counts.

    On a cholesterol and BG level, my family genetics are something that should be studied. While I started my diet at 234.8# on 2/15/2011 (I'm 5'3" and 47 y/o female) my total cholesterol was 167 and my HDL was 54. My 102 y/o grandmother however, has a total cholesterol of 155 and an HDL of 115! My 76 y/o mother also has the same great results but her HDL is "only" 109. Neither of them are on any medication for cholesterol and both of them eat a diet fully based on things we berate on this blog (cookies, bread, ice cream, fried foods, etc). Neither are overweight either. I'm eager to see what my levels become when I reach my goal weight. Maybe I can surpass that HDL of 115!

  • nina

    6/3/2011 9:39:20 PM |

    I tried that before I posted and it tells me I'm already subscribed.


  • Ron Saunders

    6/5/2011 8:06:56 AM |

    About 15 years ago I went on a fast and had only water.  The fast lasted for 10 days.  No green tea.  Just water.  After 18 hours, I completely lost any hunger.  Meanwhile I continued to cook meals for my family.  I also continued to go to work every day.

    The experience seemed wonderful.  I had been suffering badly from asthma, and all symptoms disappeared!  I could have kept going forever without eating.  However, after 10 days I started to have problems with urination.  I began excreting small, hard pellets.

    I went to the doctor, and he exploded.  "You bloody fool!" he said.  I had altered the ketone content of my blood.

    So I started eating again.  My first meal was brown rice (no salt).  It was the most beautiful meal I ever had.  Gradually I returned to normal eating.  Gradually I returned to my asthma symptoms. Gradually all meals started tasting the same.

    Did I lose weight?  I'm not sure, as my ketone problem overshadowed all else.  Did I need green tea or anything else to curb my appetite?  No, plain water (not even distilled or bottled water, but tap water) was good enough. Do I recommend fasting?  In moderation.  10 days is far too long.

  • Gabriella Kadar

    6/6/2011 3:20:06 AM |

    Is the fluoride content of any tea (Camellia sinensis) not an issue?  Data on ppm fluoride vary but they all appear to be quite high and much higher than water fluoridation levels.

  • David

    6/7/2011 8:37:20 PM |

    Try Jasmine Tea which is green tea with Jasmine flowers.  Much tastier.
    I don't like plain green tea myself, but I love Jasmine tea.

  • Renfrew

    6/8/2011 8:08:38 AM |

    There is only one problem with green tea: Pesticides.
    Most green tea is imported from India or China because it is the cheapest. On testing, a serious amount of pesticides, fungicides, microcides is found regularly. I wonder if this diminishes the health aspect of green tea.
    I used to buy organic green tea from Japan but after Fukushima that option is also out.
    Still, certified organic is the only option left, I suppose.

  • nina

    6/8/2011 8:04:07 PM |

    Just tried again and I get the same message 'You're already subscribed'.  Pity that Feedburner no longer delivers to me.


  • GaryR

    6/9/2011 9:43:01 AM |

    Started IF HFLC diet three months ago. 30 lbs lost and A1c down to
    5.1 !! (was 6.7 ) . Curiously I have been drinking green tea during the daily 18 hour fasts and hunger is a rare occurance,  hunger pains last only a few seconds. The tea helps,  body and mind trained to not think about food until
    nightly free for all. Thank you, Dr. Davis and contributors>

  • majkinetor

    6/9/2011 1:37:31 PM |

    2 Gabriella

    Flouride IS an issue with green tea. There are known cases of flourde poisoning with excessive green tea drinking - woman drinking equivalent of 20-30 green tea cups per day. This isn't something to worry about on regular usage but if you do it on IF with reduced nutrient input and more frequently to reduce appetite it can become a problem.

    White tea has lower content of fluoride as it is harvested when plant is still young. It is much more expensive but overall better then green tea due to less processing and lower fluoride content.

    Coffee works for me absolutely amazing in reducing hunger. To some people, however, it works the opposite way. My friend develops hand tremor, nervousness, and heat. The same thing she got from the green tea but not other teas. Caffeine might be problematic for some I guess, or maybe tannin. We are currently in the process of isolation of such substance.

    To reduce appetite, I found the following valuable:
    - Garlic, fresh, in tomato juice (parsley can be included to block the smell). The capsule doesn't work.
    - High intensity exercise, short bursts of 15-20 minutes will shut down digestive engine and you will not be able to eat for hour at least.
    - Marijuana restriction - its usage during fat loss might be problematic due to activation of CB1/anandamide system.
    - Periodic IF can learn body to handle prolonged food abstinence. I find that 16-24 hours fast is enough.
    - Almonds, 10-15g, are cool, especially if you tend to go crazy before sleep - its mostly fat which doesn't rise insulin during night. 2g CHO, 3.5g MUFA, 1g PUFA, 2g P is enough to make your hunger go down at least a bit and still keep your insulin down.
    - Water

    I would suggest extensive supplementation during IF - especially Vit C (at least 2g as frequent as possible), Mg, Iodine, Selenium, Idebenon.

  • Sifter

    6/10/2011 4:13:39 AM |

    Drs. Davis or Taylor (or anyone else) have you noticed any issues with accumulated caffeine intake from multiple cups of Green Tea throughout the day?

  • Cate

    6/12/2011 8:22:10 PM |

    Dr. Davis, I hadn't heard about the dangers of pesticide use relating to green tea (as mentioned by Renfew, above) this a viable concern?  Since green tea is loaded with antioxidants, do the benefits outweigh the risks in this case?

    I have been drinking about two to three cups of Tazo Zen Green Tea for quite awhile now (hot, as well as chilled), and enjoy it very much.  It does seem to curb cravings quite well.  I also notice increased energy without the edgy side effects that coffee sometimes causes.  Before Tazo, I was not a big fan of the taste of green tea, but the Zen blend also contains lemon verbena, spearmint leaves and lemongrass, which enhances the flavor and makes it quite delicious--providing an "aromatherapy experience" along with the tea consumption.  Smile

  • Evolutionarily

    6/21/2011 7:28:23 AM |

    Thank you for your informative comment JLL!

  • azzy

    6/27/2011 12:15:19 PM |

    me too!i keep hearing about green tea for fasting, so i took it on day 2 i think and was detoxing to fast cos i took it on a empty stomach....:/

  • Logan

    9/15/2011 7:56:34 PM |

    I drink the Tazo Zen Green Tea from Starbucks. I prefer this green tea over any others, however I have noticed extreme dizziness when I drink this tea. Has anyone experienced this? I even bought the tea bags to brew at home, I do not add any sweetener and love the taste. I occasionally drink black tea or soda and do not get the same dizzy feeling, therefore I believe it is not caffeine causing me to feel dizzy it's just green tea. Any suggestions or comments? I like the benefits of green tea but not sure it's worth the dizziness.

  • Dr. William Davis

    9/16/2011 2:36:08 AM |

    Wacky. No, I'm not sure why this happens.

    Perhaps its some mixture or proportion of the theaflavins or other components. There are hundreds of green tea preparations available. It might be worth finding a happy alternative.

  • Wendy Rahilly

    11/25/2011 3:50:05 PM |

    I have been using green tea for years in weight loss.  You are right, it is not a "speedy" remedy and you will only recognize small affects it has, however, it does work.  On average, it is said that you can burn anywhere from 70 to 80 calories a day drinking green tea.  This is assuming you are drinking at least 3 to 4 cups daily.  It should be combined with water and a healthy diet and exercise.

  • Dr. H

    10/27/2012 11:38:52 AM |

    About the dizziness, I had severe vertigo in the middle of the night, i.e. at 3 am (my blood pressure was 130/100 pr 90), and the day and the night before sleeping, I consumed 4 mugs of green tea. The vertigo was associated with vomiting (which relieved the vertigo for a while). The vertigo lasted till the next day (vomited 4x). The green tea was a gift from a friend who came back from China-loose dried leaves. After that episode, I think I can't make myself to drink green tea again.

  • Jennifer

    2/20/2013 7:12:45 AM |

    I sometimes do a morning 'flush' of green tea, up to 4 freshly brewed mugfuls, with the addition of a squeeze of fresh lemon, which complements the taste and gives extra benefits, vitamin c and supporting detoxification.

    I recently saw a BBC documentary which demonstrated an optimal brew time of 7 minutes for maximum anti-oxidant release.

    Also, the cooled teabags are an excellent beauty treatment for the eye area, squeeze excess moisture and relax for a few minutes.

    Am reluctant to extend beyond midday due to stimulating effect of caffeine, how about switching to other teas that deliver other useful benefits? Ginger, fennel, liquorice come to mind.

    Blessings of health