Caffeine and your metabolism

Caffeine increases the level of circulating fatty acids. This has been shown to increase the oxidation of these fuels, hence enhancing fat oxidation. Caffeine has been used for years by runners and endurance people to enhance fatty acid metabolism. It’s particularly effective in those who are not habitual users.

Caffeine is not an appetite suppressant. It does affect metabolism, though it is a good question whether its use truly makes any difference during a diet. The questionable rationale for its original inclusion in diet pills was to make a poor man’s amphetamine-like preparation from the non-stimulant sympathomimetic phenylpropanolamine and the stimulant caffeine. (That you end up with something very non-amphetamine like is neither here nor there.) The combination drugs were called “Dexatrim” or Dexa-whosis (as in Dexedrine) for a reason, namely, to assert its similarity in the minds of prospective buyers. However, caffeine has not been in OTC diet pills for many years per order of the FDA, which stated that there was no evidence of efficacy for such a combination.

From Goodman and Gilman’s The Pharmacological Basis of Therapeutics:

Caffeine in combination with an analgesic, such as aspirin, is widely used in the treatment of ordinary types of headache. There are few data to substantiate its efficacy for this purpose. Caffeine is also used in combination with an ergot alkaloid in the treatment of migrane (Chapter 39).

Ergotamine is usually administered orally (in combination with caffeine) or sublingually […] If a patient cannot tolerate ergotamine orally, rectal administration of a mixture of caffeine and ergotamine tartarate may be attempted.

The bioavailability [of ergotamine] after sublingual administration is also poor and is often inadequate for therapeutic purposes […] the concurrent administration of caffeine (50-100 mg per mg of ergotamine) improves both the rate and extent of absorption […] However, there is little correspondence between the concentration of ergotamine in plasma and the intensity or duration of therapeutic or toxic effects.

Caffeine enhances the action of the ergot alkaloids in the treatment of migrane, a discovery that must be credited to the sufferers from the disease who observed that strong coffee gave symptomatic relief, especially when combined with the ergot alkaloids. As mentioned, caffeine increases the oral and rectal absorption of ergotamine, and it is widely believed that this accounts for its enhancement of therapeutic effects.


Nowadays most of researchers believe that the stimulatory actions are attributable to the antagonism of the adenosine. Agonists at the adenosine receptors produce sedation while antagonists at these sites, like caffeine and theophylline induce stimulation, and what is even more important, the latter substance also reverse agonists-induced symptoms of sedation, thus indicating that this effects go through these receptors.

Another possibility, however, is that methylxanthines enhance release of excitatory aminoacids, like glutamate and aspartate, which are the main stimulatory neurotransmitters in the brain.

As to the side effects: methylxanthines inhibit protective activity of common antiepileptic drugs in exptl. animals in doses comparable to those used in humans when correction to the surface area is made. It should be underlined, that although tolerance develop to the stimulatory effects of theo or caffeine when administered on a chronic base, we found no tolerance to the above effects . This hazardous influence was even enhanced over time. Therefore, it should be emphasized that individuals suffering from epilepsy should avoid, or at least reduce consumption of coffee and other caffeine-containing beverages.


Nicotine does affect the metabolism of caffeine, and some have suggested it as a way to reduce caffeine levels in your body. The usefulness of this is dubious at best – if your blood pressure is high and you’re experiencing anxiety, adding a stimulant usually isn’t the best idea.

45 thoughts on “Caffeine and your metabolism”

  1. Effects of Caffeine after Bariatric Surgery

    I am curious as to the effects of caffeine after bariatric surgery. Since caffeine is processed in the stomach, where does it go and how does it affect the body after the stomach had essentially been removed? Is the effect less or more? Is there a danger limit after this type of surgery? I still feel the need for the caffeine for alertness, but I get very testy after ingesting it.
    I was warned away from caffeine after surgery, by my surgeon, because of the (then) belief that it caused dehydration. Since the current study has debunked that myth, I felt relieved and continued drinking my espressos. Now I am hit with this irratability factor (from those I work with, and family members)& wonder if I should take another look. Any clinical evidence or links out there?

    1. One thing I have done when

      One thing I have done when drinking caffeine from coffee/soda is to decrease or stop drinking water. I might drink some decaffeinated drinks, but not plain water.

      I usually don’t notice it at 1st until I start feeling tired and strung out. If I drink plenty of water even if drinking coffee/soda I am ok.

      One thing to consider is that you have spent the time, energy and money to get the surgery to improve your life. Hopefully you are now able to live more of an active life. Don’t hurt yourself with something which could possibly be harmful to you. I would listen to my doctor. If he did a good job with your surgery don’t you think he might just know what he is talking about?

      Good luck to you.

    2. Caffeine after c-section made me testy

      I had a c-section 2 months ago and recently began drinking coffee again. But then I noticed I’ve been getting really testy and started get sweaty and almost lose control. The thing is I was never warned this would happen. So here I am at almost 5 in the morning trying to figure out what’s the connection. Although it’s not a pleasent feeling it’s good to know I’m not alone. What I would like to know if drinking decaf will be better considering decaf still has caffeine. And also will this ever go away. I really enjoy having my cup of Folgers to start out my day.

  2. Are there cases of drug

    Are there cases of drug addicts using methylxanthines ? Have people even considered using this as a drug ?

  3. re

    I guess many accidents occur because people don’t know they are epileptic or they don’t really know what could harm their body.

    1. I think I need more…

      If you will do a little research into the ill-effects of caffeine (especially an excess of it!) you will discover that there are far too many side effects (including death!) associated with a higher consumption level of caffeine. A much safer way of burning more fat is simply to EXERCISE more. And exercise on a regular basis will actually promote a natural high in addition to burning the extra fat you want to lose.

  4. Nice place, cheap alcohol i

    Nice place, cheap alcohol i guess people are storming in there, anyway hopefully for them they know that abusing alcohol hurts their bodies.

  5. Cofee

    Caffeine has a few good influences if it is taken in the wright quantities like it helps with hearth disease,but if it is taken too much it has very bad effects

    1. Caffeine

      Considering the ill effects that coffee/caffeine have on the body, such as increased heart rate, rapid, irregular heartbeat, increased blood pressure, increased cholesteral (which can contribute to heart attack), I would think the risks of caffeine use would outweigh the so-called benefits. Do the research yourself, (as I just have) and you’ll discover the side effects and risks far outweigh any benefits of it’s use.

      1. This is dependant entirely on the individual, amounts used, rate of consumption both daily and over periods of time. Simply saying that it’s bad more than good is like saying a ham sandwich is objectively better than a turkey sandwich. Caffeine is like all of the legal drugs we take, nicotine, alcohol, etc. It’s about how you use it, how much, and why.

  6. weight loss

    I used to drink a plain venti americano from starbucks everyday for lunch. I lost 25 pounds in a little less than 2 months..

    Probably not too good for the body but eh.

    1. weight loss

      if you only had coffee for lunch for 2 months, you were starving yourself. While you were doing that, you were shutting down your metabolism. Neither are good because you teach your body that you can’t be trusted and it will store EVERYTHING you put in your mouth after that, hence gaining the 25 pounds back and a few more for safety, in case you do it again. Do yourself a favor, keep having coffee, but have 5 small meals a day that have protein in them as well as a veggie at each meal, and starchy carbs 2-3x a day. Oh, and 2 pieces of fruit and half your body weight in ounces of water and TRUST me, you will lose weight and keep it off! (No cutting out food groups either!) Just think about how our great grandparents ate before all the processed junk!

      1. horrifying.

        who the hell has the time and money to spend on the crap you’re talking about? Recognize that your diet is a privelege, not worthy of a sermon.

        1. Who has the time and money to

          Who has the time and money to eat fruits and vegetables? non-morbidly obese people who don’t do the majority of their shopping in gas stations.

          1. immediately, it does cost

            immediately, it does cost more money to go out and purchase enough HEALTHY food to make 5-6 small meals per day. and it takes up a decent amount of time to plan out those meals and pack them up.. BUT in the end, isn’t it less money than you will be spending on diet/weight loss and/or medical bills when you are possibly over weight and therefor more prone to illnesses? i’d much rather go to a produce stand and buy my fruits and veggies and buy some chicken at a grocery store that has it on sale and then pack up some small meals than head out for lunch every day at work and buy one bigger disgusting meal from the various places near my work– wendy’s, mcdonalds, etc. what IS ridiculous isn’t the thought of planning ahead and eating right, but instead using laziness as an excuse to eat bad most of the time. i was in college, too. i still packed my food and ate healthy and it didn’t even cost that much to do it.

          2. My OPINION.

            Ok i can understand with it taking a little bit to plan and pack the meals. I have done it before and it can get a little costly depending on what you buy.

            Here are some things that arent high in calories and not really pricey. Most stores have regular sales on the fruits and vegetables anyway.

            Bag of salad mix
            Granola Bars
            100-calorie packs of cookies or crackers (i dont recommend because I feel they aren’t worth it.)

            The list goes on and on.

            What i used to do for a snack is have an apple or hard boiled egg. eggs have about 80-90 calories each.
            you hard-boil 7-12 every week and there could be a snack. what i did with the eggs to make them a little healthier is before i ate them i would cut them in half and take out half of the yolk because the yolk contains most of the fat and cholesterol.

            and what someone said about buying chicken at the store. Yes chicken is better for you then red meats, but they feed those animals so many steroid like substances it not too good for you anyway. some places give chickens so many growth supplements that they cant even stand up and walk around.

            Another way to eat healthier is start hunting. Game animals are so much healthier to eat then what you buy at the store. Especially Game birds. Pheasant is smaller then chicken but in my opinion tastes 10 times better.

            I hunt and can honestly say that cooking the food shows its healthier. like making hamburgers out of ground venison instead of ground beef. you dont see all that fat dripping off like you would for beef.

            Well this is just my opinion so hopefully it helps anyone who cares to read it.

          3. Only eating half a yolk is

            Only eating half a yolk is also depriving you of a large portion of the protein. The USDA Nutrient Database lists an egg yolk as having 2.7 grams of protein. The egg white is listed at 3.6.

            Cholesterol is not nearly as responsibly for high cholesterol as saturated fat is, and one egg only has 1.5 grams of saturated fat. Studies have shown ( that even eating over six eggs a week will not increase your risk of heart disease or stroke.

            I’m not a working for an egg company or anything, I just use to do the same thing as you and now regret wasting all that protein, healthy fat, and essential amino acids.

          1. Good luck trying to treat

            Good luck trying to treat that personality disorder you have! 🙂

      2. Calm down. I believe she said

        Calm down. I believe she said “for lunch”, not “that’s all I had all day”. In either case, a lot of people don’t have time to eat (let alone make) 5 small nutritious meals a day. I’m a college student. I tried it for about 3 days before I realized it was ridiculous.

        1. It’s not ridiculous at all,

          It’s not ridiculous at all, by a ‘meal’, he dosn`t necessarily all out meals with patatoes and carrots and beef….. If you can bring yourself almonds, or a greek yogourt to munch on, thats already extra protein intake that will neutralize your body’s survival instinct in storing fats. Simply put, the more often you eat, the less you will store. It’s not about quantity, it’s about quality and frequency.

    2. I was diagnosed with lymphoma

      I was diagnosed with lymphoma and after the chemo and
      breast reconstruction after mastectomy I lost about 30 pounds, so don’t feel bad about drinking caffeine because i’m pretty sure my method was a lot worse haha

  7. Needs to cite source

    On caffeine *not* being an appetite suppressant. A quick google, and pretty much every link you click contradicts that…

    1. I dont think caffeine

      I dont think caffeine suppresses your appetite as well as drinking lots of water.

      And drinking coffee to suppress appetite is not a good idea. And it is not very effective for the cause of dieting. You feel full temporarily from the increase of your glucose levels in your blood. But your blood sugar levels will drop sharply, leading to a painful realization that you need another cup of Joe. Your glucose levels are maintained by insulin. Your body will regulate this unless you are a diabetic.

      Also coffee and most caffeinated drinks have ALOT of sugar in it. The sugar that you do not use to function will be stored as FAT all over your body.

      1. caffeine and diabetes

        I have been a heavy consumer of coffee and soda since my teens. I am now 58. In my mid 30’s I was diagnosed with diabetes. I was given a list of ‘free foods’ which included coffee, non sugar sweeteners, and s/f sodas provided I was careful with fruit flavored drinks since they hide the sugar content claiming sugar free. I am now finding caffeine is NOT really a freebie as taught in diabetic classes.

        My health has been on a downward spiral for the last 10 years or so. My diabetes, (for 15 years) controlled with diet and exercise and 1 glipizide pill kept me at a 5 A1c. The last few years I have been diagnosed with gerd, IBS, hiatal hernia, fibromyalgia, disabling rheumatoid arthritis (after suffering a very solid frozen shoulder misdiagnosed for 2 years!) an interstitial lung disease requiring me to be on oxygen and my A1c is now at 8. I am taking 2 different medications and am on 60 units of insulin a day as of last week (went up from 40).
        I have mild bone loss and my liver is on watch due to all these medications. How much of my many conditions can be exacerbated by the use of caffeine? I drink nearly 8 cups of coffee in the morning then switch to either ice tea or diet sodas. Also would switching to 1/2 caf or non caf. coffee and sodas correct any problems caused by the caffeine,
        and finally, are the problems from caffeine a accumulative effect over a long period of time or more immediate?
        Perhaps I never had diabetes and perhaps much of the current epidemic is also a large part caffeine and not just all the wonderful carbs and sugar being consumed! Why isn’t the medical industry and the FDA shouting this at the top of their lungs!!!!!

        1. sweetners

          My husband and I had been using sweetners for about 6mo when he was diagnosed with DMII, and we noticed aches and pains in our joints, and a heavy sensation in our chest. We stopped all sweetners and after a couple of weeks, all of our aches and pains went AWAY!!! We used a lot of splenda and other sweetners at that time, but since then have stopped. We feel so much better!!!

        2. Coffee

          Eight cups of coffee in the morning? If you value staying alive stop drinking coffee altogether. Replace it with juices or pieces of fruit. You will get better. No more sodas.
          Maximum of 4 cups of tea per day and no coffee until you recover.

        3. coffee

          i am a heavy coffee drinker myself but holy cow!! eight cups? thats a lot of coffeee in the morning. and i agree….staying away frrom the sodas is a very good idea. especially for anyone trying to lose  weight. water is the best choice. and  if u just cant stand water add a smalll amount of crystal light. sugar free or not, its better for u   than a soda. a lemon wedge  with water is the best tho. and if u want more energy without the caffeine, go for a run. exercise will boost ur energy levels believe it   or not….

        4. Dosage of Caffeine

          Hi there,

          I think one mistake your making is that, Caffeine as a substance is causing your conditions, and is not good for you, which is not the case. The problem’s you are having, can be brought out by caffeine, but only by excess consumption of it. The FDA reccomends not to go over 300 mg, and with 8 cups of coffee, that is already 640 mg of caffeine, and then eahc diet soda is 50mg of caffeine, and black and green tea have 80mg of caffeine each. So your problems are from the dramatic overuse of caffeine, not from caffeine itself

      2. Coffee only has a lot of

        Coffee only has a lot of sugar if you add it to the drink.  Also you can use steva which is derived from and herb, which helps to control Blood sugar.  So add Stevia and no cream and coffee is great for dieting.  But Water is very important as well.  Lots of Water on any diet.  It helps with digestion, hydrations and mobilizing toxins.

  8. I have never liked coffee too

    I have never liked coffee too much, I mean, I don’t smoke and I’m not one of those maniacs that can’t get out of bed without a cup of coffee in their hands. After reading the last online merchant reviews here: {edited}, coffee ain’t that expensive but after drinking a small cup I feel that I’ve run out of calcium!

  9. Caffeine and your metabolism

    Excess of every thing is bad. Any how i used to take some pills of Caffeine during my microsoft tests. Due to this i got good response to achieve my task. But after it i have to leave due to some excess metabolic wastes in my body.

  10. I’ve been eating less for the

    I’ve been eating less for the past month.. but isee no change in my oants size.. i lost 9 pounds.. but i want to lose more wight in less time.. my goal is to lose 10 more pounds.. if i cut junk and eat lass carbs with a lot of black coffee would that do? can i lose 10 pounds by just doing this? i’m a smoker and i drink 2-3 mugs of black coffee per day..

    1. reply

      My advice to you is to not over do it because you will end up hurting yourself more in the process. I don’t care if you lose 1-2 pounds at a time… eventually you’ll hit your 10 pounds mark. Just take it real slow so that the organism has time to acknowledge all the changes.

    2. i would have cut the junk b4

      i would have cut the junk b4 eating less. but cutting food intake so much your losing muscle weight thats why your dropping weight and not pant size

  11. Metabolism

    It will take some time for your body to re-adjust to having no caffeine after about 3 days to a week you should be back to normal…increase your fiber intake (lots of fruit) and as for tiredness you can take naps or just battle through it. I did a caffeine detox and wrote about it here to reset my caffeine clock so to speak, now I only have coffee a few times a week and it works great.

  12. Coffee

    Coffee is a natural diuretic Hence the reason it can cause weight lose. but adding creamer and suger will counter act the losing process and your body will feed off the sugars in the creamer and ofcourse sugar. Coffee aslo helps the heart rebuild itsself. I love the healing properties it causes. For all you doubters try it for one month at least drink 4 cups a day black coffee and tell me your heart and body doesnt feel better make sure you have your recomended water intake. Hydrate for the lose of fluids from the diaretic Thank you have fun in this journey and you could lose a massive ammount of weight with Black coffee and excersice and plenty of water to reduce the water weight. Love it

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