Caffeine does seem to support fat-loss owing to a variety of actions – increased energy production, breakdown of fat and appetite suppression. Additionally, caffeine improves exercise performance, muscle contraction, mental focus, skill levels and therefore, the quality of training. A word of caution though – caffeine seems to work best when combined with an exercise and diet plan.
From the ‘not-so-skinny’, looking to lose fat to elite athletes wanting to improve their performance, caffeine is being used by the whole town and his wife. In fact, caffeine is the most used drug in the world for a variety of purposes (Laurent et al., 2000).
A body-builders ‘pre-workout drink’, a footballer’s ‘pre-match drink’, an office goer’s ‘switch-on drink’, a student’s ‘study-aid’ – they all contain caffeine. Fat-loss supplements, more often than not, contain caffeine as the main ingredient. Most energy beverages (coffee, tea and cola) and stimulant drinks like Red Bull all contain caffeine. Similar to fat-loss supplements, caffeine is the commonest ingredient in energy drinks too – levels range between 70 to 200mg per 16oz serving (Higgins, Tuttle, & Higgins, 2010); some energy drinks contain 500mg or more per can – these, however, have largely been discontinued since 2011 (Baldwin, 2013).
Not surprisingly, caffeine has become synonymous with the phrases fat-loss, energy-drink or pre-workout drink.
What is Caffeine?
Caffeine is a stimulant drug. Pharmacologically, it is an adenosine receptor antagonist (Jones, 2008). In simpler terms it means that caffeine acts by blocking actions mediated through adenosine receptors. Now, this receptor is responsible for lowering the levels of stimulant hormones like adrenaline, dopamine and serotonin.
By blocking adenosine receptors, caffeine indirectly causes increased levels of these hormones. Therefore, the more caffeine you take in, higher the levels of adrenaline (and other stimulant hormones) in your system. These hormones then cause most (but not all) the actions of caffeine.
What Does Caffeine do for Me?
Will caffeine really help me lose fat? And, is it really worth it to buy that caffeine-containing fat-loss supplement? Based on current scientific evidence, the answer may be a resounding ‘yes’. Whether you are looking to lose fat, improve performance at your workplace (or as a sports person) or generally feel good, caffeine seems to be the solution.
So, what exactly does caffeine do for me, you might want to ask? And, what justifies the use of caffeine as a fat-loss drug? To get an answer, all you need to do is to have a look at some of the actions that caffeine has on your system and you will agree that caffeine does pack a punch.
Here is What Caffeine Seems to do Your System
Caffeine owes its amazing fat burning property to its ability to cause a significant increase in the production of energy. Research suggests that energy levels can remain high for as long as 3 hours after consumption of caffeine (Astrup et al., 1990). Caffeine also causes lipolysis (breakdown of fat). Furthermore, caffeine has been shown to have profound effect on exercise performance as well – more on the fat-loss actions of caffeine follows.
It is common knowledge that caffeine seems to improve cognition, wakefulness and alertness. It also enhances the ability to acquire of new skills (Lieberman, Tharion, Shukitt-Hale, Speckman, & Tulley, 2002). These actions contribute towards a better focus and improved technique during exercise/ training sessions. Additionally, caffeine has been shown to improve muscle contraction (Lopes, Aubier, Jardim, Aranda, & Macklem, 1983; Kalmar & Cafarelli, 1999) and secretion of the feel good hormones – endorphins (Laurent et al., 2000) – all these actions justify the presence of caffeine in ‘pre-workout’ supplements.
In short, caffeine…
Enhances fat loss
Improves exercise ability and muscle contraction
Improves cognition (focus) and task learning
Does Caffeine Really Cause Fat Loss?
Scientific evidence seems to support caffeine’s claim as a top fat-loss drug. A few theories have been proposed to explain fat burning abilities of caffeine.
Caffeine causes mobilization of fat from fat (adipose) tissue (Laurent et al., 2000; Ivy, Costill, Fink, & Lower, 1979; Erickson, Schwarzkopf, & McKenzie, 1987; Spriet et al., 1992). The most agreed upon hypothesis is that caffeine stimulates the secretion of adrenaline (Graham et al., 2001; Battram, Graham, Richter, & Dela, 2005). Adrenaline, in turn, causes release of fat from adipose tissue. The free fat is then transported to exercising muscles where it is utilized as ‘fuel’.This caffeine-induced use of fat as fuel has a dual advantage – it causes fat loss and improves exercise performance.
Release of fat from adipose tissue and its subsequent burning as fuel for exercises will, needless to say, reduce body fat. Furthermore, the preferential use of fat over carbs as exercise fuel – known as the ‘glycogen-sparing effect’ of caffeine – ensures improved exercise performance. Glycogen saved during the initial part of training as a result of caffeine ingestion will help you keep going longer during training sessions. Caffeine also induces formation of new glycogen and thus help is recovery after an intense training session.
Caffeine improves the functioning of heart as a muscle pump – a stronger and faster heartbeat is the net result (Mayo Clinic Staff, 2009). Elevated blood pressure and peripheral resistance in blood vessels is also observed. The speeding up of these processes helps in bumping up your basal metabolic rate (improves calorie burning) and contributes indirectly to fat loss.
Other methods proposed for caffeine’s fat loss abilities are appetite suppression (reduction of hunger) and diuresis (water loss through urine). However, the evidence in support of these actions seems to be flimsy. Also, these do not contribute much to loss of existing body fat.
In a nutshell, caffeine supports fat loss through the following process:
Mobilization of fat from adipose tissue
Utilization of fat as fuel for exercise
Improved exercise performance
Enhanced metabolic rate
Appetite suppression (small extent)
Other Side of the Argument
There are those who believe that caffeine does nothing to help you lose fat. Some even go to the extent of suggesting that caffeine may, in fact, add weight! This is because, most speciality coffees are high in calories and fat, they say .
However, if you are on a ‘fat-loss mission’, there’s a very slim chance that you’d be picking up anything that has excess calories or fat in it. Furthermore, caffeine in fat-loss supplements – as powder, tablets or pills – is usually present in the anhydrous form. This form of caffeine is way more potent than that present in beverages like coffee, tea, cola or energy drinks. What’s more, fat-loss supplements will not contain excess calories or fat.
Also, there is enough anecdotal evidence which supports the role of caffeine in improving fat-loss and exercise performance – you wouldn’t have had soccer players drinking four cups of black coffee before every single game, if that hadn’t been the case!
A word of caution though – drinking loads of black coffee or using a fat-loss supplement alone won’t do you much good. Caffeine works best when combined with a well-planned exercise and dietary program.
What Happens When you Have Too Much of Caffeine?
Occurrence of side effects to caffeine ingestion is subjective. In those sensitive to caffeine, unpleasant effects can sometimes occur at a dose as little as that contained in a cup of coffee – 200mg (Clauson, Shields, McQueen, & Persad, 2008; Calamaro, Mason, & Ratcliffe, 2009). However, in most people a dose of more than 500-600 mg (more than 4 cups of black coffee) is required to cause side-effects (Mayo Clinic Staff, 2009). As you may well have guessed, there are those who can tolerate doses up to 800mg.
Too much caffeine in your system can cause:
Nervousness (jitteriness or restlessness)
Insomnia (lack of sleep)
Most proprietary fat-loss supplements will contain other stimulants in addition to caffeine. And, as such will have graver side-effects profiles than caffeine alone. Please do check the label for contents before you buy a fat-loss supplement.
Astrup, A., Toubro, S., Cannon, S., Hein, P., Breum, L., & Madsen, J. (1990). Caffeine: a double-blind, placebo-controlled study of its thermogenic, metabolic, and cardiovascular effects in healthy volunteers. Am J Clin Nutr., 51, 759-767. Online Source
Baldwin, A. (2013). What Drinks Contain 500mg of Caffeine. Ref Type: Online Source
Battram, D. S., Graham, T. E., Richter, E. A., & Dela, F. (2005). The effect of caffeine on glucose kinetics in humans–influence of adrenaline. J Physiol, 569, 347-355. Online Source
Calamaro, C. J., Mason, T. B., & Ratcliffe, S. J. (2009). Adolescents living the 24/7 lifestyle: effects of caffeine and technology on sleep duration and daytime functioning. Pediatrics, 123, e1005-e1010. Online Source
Clauson, K. A., Shields, K. M., McQueen, C. E., & Persad, N. (2008). Safety issues associated with commercially available energy drinks. J Am Pharm.Assoc.(2003.), 48, e55-e63. Online Source
Erickson, M. A., Schwarzkopf, R. J., & McKenzie, R. D. (1987). Effects of caffeine, fructose, and glucose ingestion on muscle glycogen utilization during exercise. Med Sci.Sports Exerc., 19, 579-583. Online Source
Graham, T. E., Sathasivam, P., Rowland, M., Marko, N., Greer, F., & Battram, D. (2001). Caffeine ingestion elevates plasma insulin response in humans during an oral glucose tolerance test. Can.J Physiol Pharmacol., 79, 559-565. Online Source
Higgins, J. P., Tuttle, T. D., & Higgins, C. L. (2010). Energy beverages: content and safety. Mayo Clin Proc., 85, 1033-1041. Online Source
Ivy, J. L., Costill, D. L., Fink, W. J., & Lower, R. W. (1979). Influence of caffeine and carbohydrate feedings on endurance performance. Med Sci.Sports, 11, 6-11. Online Source
Jones, G. (2008). Caffeine and other sympathomimetic stimulants: modes of action and effects on sports performance. Essays Biochem., 44, 109-123. Online Source
Kalmar, J. M. & Cafarelli, E. (1999). Effects of caffeine on neuromuscular function. J Appl.Physiol, 87, 801-808. Online Source
Laurent, D., Schneider, K. E., Prusaczyk, W. K., Franklin, C., Vogel, S. M., Krssak, M. et al. (2000). Effects of caffeine on muscle glycogen utilization and the neuroendocrine axis during exercise. J Clin Endocrinol.Metab, 85, 2170-2175. Online Source
Lieberman, H. R., Tharion, W. J., Shukitt-Hale, B., Speckman, K. L., & Tulley, R. (2002). Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land. Psychopharmacology (Berl), 164, 250-261. Online Source
Lopes, J. M., Aubier, M., Jardim, J., Aranda, J. V., & Macklem, P. T. (1983). Effect of caffeine on skeletal muscle function before and after fatigue. J Appl.Physiol, 54, 1303-1305. Online Source
Mayo Clinic Staff. (2009). Caffeine: How much is too much? Ref Type: Online Source
Spriet, L. L., MacLean, D. A., Dyck, D. J., Hultman, E., Cederblad, G., & Graham, T. E. (1992). Caffeine ingestion and muscle metabolism during prolonged exercise in humans. Am J Physiol, 262, E891-E898.
About the Author: Kelly Johnson
Kelly's background is in sports science, and after leaving university with a first she has developed a passion for finding out which supplements work and how they affect the body.
When she finally grabs some downtime, Kelly loves to trek; so she can usually be found up a mountain somewhere.
Disclaimer: Our reviews and investigations are based on extensive research from the information publicly available to us and consumers at the time of first publishing the post. Information is based on our personal opinion and whilst we endeavour to ensure information is up-to-date, manufacturers do from time to time change their products and future research may disagree with our findings. If you feel any of the information is inaccurate, please contact us and we will review the information provided.