What Is Caffeine?
Caffeine is a xanthine alkaloid compound that stimulates the central nervous system, temporarily increasing alertness. It is the most widely consumed legal psychoactive agent (a substance that affects brain functioning) in the nation.
Caffeine is found in the beans, fruit or leaves of over 60 plants and therefore, caffeine may not be listed on the label of a supplement or functional food but instead, you may see some of the following listed: guarana berries, mat, chocolate or cocoa, Camilla sinensis (the leaves of this plant are used to make tea) or kola nut. Some of these plant-based sources of caffeine include other stimulants as well including theophylline and theobromine.
The most notorious use of caffeine is to support mental alertness and help ward off mental fatigue. However, there are many other potential applications as well.
Caffeine is used to fight the mental and physical fatigue of training (traditional athletic training or military training), support other issues associated with eccentric exercise and support glycogen resynthesis.
In addition, caffeine can be found in weight loss products, energy drinks and combined with analgesics for treating headaches.
Is It Safe?
In the United States, caffeine is Generally Recognized as Safe (GRAS). However, each individual's ability to tolerate caffeine differs. Some people experience negative side effects after ingesting very small quantities of caffeine while others can drink a pot of coffee a day with no problem (though this isn't recommended!).
Doses of 250-300 mg or more per day can lead to a rapid, irregular heartbeat and difficulty sleeping. Ingesting extreme quantities, 10-14 grams (or 150-200 mg per kg body weight) can lead to death.
It is recommended that pregnant women consume below 300 mg of caffeine per day. Caffeine in high doses can lead to spontaneous abortion, low birth weight and/or premature birth.
In addition, experts recommend the following individuals avoid caffeine altogether: those with anxiety disorders, cardiac problems, glaucoma and high blood pressure. Caffeine can increase the risk of adverse side effects when taken with certain over the counter or prescription drugs including diethylpropion (Tenuate), epinephrine, phentermine (Ionamin) and pseudoephedrine (Sudafed), stimulants, riluzole (Rilutek) phenylpropanolamine and clozapine.
Therefore, it is always wise to check with your personal physician if you are concerned about your caffeine intake or caffeine's potential interaction with a medical condition or medication.
Many supplements and beverages do not indicate how much caffeine is in them. If you are concerned, call the company and ask.
In a USDA study that examined the caffeine content of energy drinks, researchers found that these beverages, in general, contain the amount of caffeine commonly found in sodas and coffee drinks.
However, supplements containing caffeine varied wildly from less than 200 mg per serving (the majority of supplements studied fell into this category) to over 800 mg (one supplement).
3 ways Caffeine May Support An Increase In Calorie Burning
1. Caffeine May Support The Increase Of Lipolysis
Caffeine may temporarily support lipolysis, the breakdown of fat.
2. Caffeine May Temporarily Support The Increase Of Thermogenesis
Caffeine, alone or in combination with other supplements, may temporarily raise one's metabolism boosting calorie burning. Keep in mind that this effect may be diminished in people who habitually consume caffeine—especially those who habitually consume large quantities of caffeine (>300mg/day).
3. Caffeine Works With Green Tea
Few people would doubt that tea is one of nature's best drinks. And, research continues to examine the many potential benefits associated with tea consumption.
In weight loss supplements, it seems that green tea, in particular the catechin EGCG, when combined with caffeine, works synergistically. This combination has been suggested to boost circulating levels of norepinehrine, which stimulates the breakdown of stored fat and stored carbohydrate.
Tips To Increase Calorie Burning
Add Activities Of Daily Living
Don't discount the calories burned during activities of daily living such as cleaning your car (versus letting someone else clean it), walking as opposed to driving, cleaning your home etc. Even if you go to the gym for an hour every day, it is vital to be active throughout the day. This is especially important for those with sedentary desk jobs.
If you are doing cardio, add one or two interval sessions every week. By increasing the intensity (in this case, varying the intensity), intervals will help you burn through calories at warp speed.
Add a little more protein. You burn more calories digesting protein than you do digesting fat and carbohydrate. Though we need all three of these macronutrients, it is a good idea to take a look at your diet and substitute protein for fat or carbohydrate if you are over-consuming either of these macronutrients.
Lift For Growth
By adding muscle tissue, your metabolically active tissue, you'll burn more calories at rest. Granted, the amount you burn at rest is often overblown, but even a few calories a day, over time, can help with weight loss or weight maintenance.
The best way to lose weight is through a sound diet and exercise program. Caffeine alone will not help you shed pounds. However, if used responsibly, you may support a boost in athletic performance and alertness as well as possibly burn a few more calories in the process.
- "Caffeine" in The American Heritage Dictionary of the English Language, Fourth Edition, 2000.
- Newall CA, et al. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
- J Pain. 2007 Mar;8(3):237-43.
- J Appl Physiol. 2008 Jul;105(1):7-13.
- Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html
- N Engl J Med 1999;341:1639-44.
- N Engl J Med 1999;341:1639-44.
- Food Chem Toxiocol 2002;40:1243-55.
- Med J Aust 2001;174:520-1.
- Ann Pharmacother 2002;36:992-5.
- Br J Clin Pharmacol 2000;49:59-63.
- Clin Pharmacol Ther 1991;50:363-71.
- Am J Clin Nutr 1999;70(6):1040-5.
- Chin J Integr Med 2009;15(1):34-41.
- Reprod Toxicol 1998;12:435-44.
- Ann Pharmacother 2002;36:992-5.
- Eur J Clin Nutr 1999;53:831-9.
- J Obes Relat Metab Disord 2002;26:593-604.
- Anal Bioanal Chem 2008;391:2811-2818
- Am J Clin Nutr 1989;49(1):44-50.
- Am J Clin Nutr 1990;51(5):759-67.
- Ann Nutr Metab. 1995;39(3):135-42.
- Obes Res 2004;12(7):1152-7.
- J ISSN 2006;3(1):35-41.
- JISSN 2007;4:10.
- Obes Res 2005;13:1195-204.