If you’ve been searching your whole life for a safe, effective “fat burning” diet aid that can help you to control how much you eat so you will lose weight and keep it off, ordinary caffeine may be the answer to your prayers. In fact, caffeine helps control your weight in four entirely separate ways:
- Caffeine suppresses appetite
- Caffeine increases metabolism
- Caffeine increases fat burning
- Caffeine enhances the benefits of exercise
On this page we explain how you can put caffeine’s power to work for you to enable you to shed fat and stay slim. Remember that caffeine can help you to cut down on what you’re eating without feeling hungry! Remember also that caffeine’s effects are additive: The amount you lose by eating less must be added to what you lose by increasing your metabolism, increasing fat burning, and increasing exercise levels to estimate the total effect caffeine will have on your weight.
The “Satisfaction Diet”: How Caffeine Suppresses Appetite
Caffeine, like most stimulants, is an anorectic, that is, a pharmacological agent that suppresses appetite. To put it simply, taking caffeine delays the onset of hunger, and caffeine taken before meals reduces the amount of food you need to feel full. Most people have coffee after eating. Although this is a pleasant custom, it’s really doing things backwards if you want to get the full weight loss benefits from caffeine. To capitalize on the ability of caffeine to help you eat less, you should take an effective dose of caffeine at least 15 minutes before you begin your meal! Here again caffeine pills can be very handy. It may be difficult to secure a strong cup of coffee 15 minutes before lunch or dinner, but you can always find a glass of water and take a caffeine pill. If you do this, by the time you begin eating you will find that your appetite has been reduced.
What is the evidence that caffeine can help curb your appetite?
Throughout its history, the natural sources of caffeine have all been utilized for their ability to stave off hunger. The Gallae warriors, semi-legendary highland raiders of Ethiopia carried balls of fat mixed with crushed coffee beans to help keep them from growing hungry during their military expeditions. In the 1556 annals of a man who was in Cortez’s company during his conquests in Central America we read of a strong cacao preparation common in that region, “This drink is the healthiest thing, and the greatest sustenance of anything you could drink in the world, because he who drinks a cup of this liquid, no matter how far he walks, can go a whole day without eating anything else.”[i] And when a mini ice age in Europe in the seventeenth century ruined crops and cut off the food supply, peasants relied on the caffeine in coffee and tea to help them endure the long wait between meals. You could say that natural sources of caffeine have been proven in the field as appetite suppressants, under a variety of harsh conditions in which controlling hunger was vital.
Caffeine’s use in enormous amounts by anorectics is unhealthy—it is rarely good to go to extremes—but it provides a graphic demonstration of caffeine’s appetite-killing power. However, the fact that anorectics find that caffeine can reduces or even virtually stops their intake of food is good evidence that, used in moderation, caffeine can help people to lose weight in a healthy way. And if caffeine in large doses can virtually eliminate hunger, it seems reasonable that, in small doses, it should substantially reduce the amount you eat. Remember that if you can reduce your appetite—and your food intake—by even 10%, you’ve turned yourself into a thin person in the long run.
How does caffeine suppress appetite and enable us to lose weight? Again, the answers seem to lie in its effects on our intricate system of neurotransmitters, the chemical substances, such as serotonin, dopamine, or acetylcholine that, among other things, tell us when to be hungry, how much energy to produce, and how much fat to burn.
As we mentioned above, regulating serotonin and other neurotransmitter systems may be one of the keys to caffeine’s appetite suppressing power. After eating, especially after eating carbohydrates and dairy products, the brain releases serotonin and other neurotransmitters that determine whether we feel hungry or full and that also have a relaxing effect. Lower serotonin levels can cause people to crave food at the same time as they feel depressed. Many anti-depressant and anti-anxiety medications achieve their therapeutic effects by increasing serotonin levels or by making the brain more sensitive to serotonin. Eating foods rich in carbohydrates produces similar effects. So, when you are edgy or depressed and consume carbohydrate-rich foods, you are medicating yourself![ii] By helping you avoid this calorie rich “medicine,” caffeine can spare you the additional fat you would have accumulated from all that pasta, candy, and bread.
Fighting the “Being Down, Chowing Down” Syndrome
Almost all of us have had the experience of feeling depressed or lethargic and turning to food for comfort and a lift. This syndrome might be called “eating your way to happiness,” and it is a downward spiral that results in Americans gaining millions of pounds every year. You could pay a therapist to try to dissipate your gloom and get you going again. Or you could try caffeine. Caffeine may give you the mental and emotion lift you need to break out of depression. It also supplies a burst of physical energy. Together these effects encourage you to increase your level of daily activity and exercise. Because exercise increases endorphin output, it helps to further dissipate your depression. Instead of a downward spiral of eating more and feeling worse, you can begin moving in an upward spiral of doing more and feeling better.
Other mechanisms by which caffeine may help to limit your appetite have also been postulated. According to Miriam E. Nelson, Ph.D. and Sarah Wernick, Ph.D., in their best-selling book Strong Women Stay Slim, “When food leaves the stomach and enters the small intestines, the intestinal lining releases several hormones. We know from experiments in animals that these hormones are powerful appetite suppressants. One of them, called cholecystokinin (CCK), also seems to contribute to the calming effects we experience after eating. CCK is especially responsive to fat in the diet.”[iii] Coffee has been shown to stimulate the release of cholecystokinin. This means that caffeine could help our bodies to generate a hormone that actually makes us feel full and keeps us from wanting to eat!
Finally, some researchers have proven that people who have taken caffeine show “reduced time to perceived gastric fullness” and that caffeine significantly delays “gastric emptying.”[iv] In other words, when you eat, caffeine makes you feel full faster and keeps your hunger satisfied longer. The important thing to remember is that caffeine has been proven to reduce your appetite, to make you feel full, and to keep you from wanting to eat. For a dieter, that’s really all the good news you need!
Experiment with your own eating habits. For a week, write down what you have for lunch every day, making careful note of the size of your portions. Don’t try to limit your food intake. Simply eat until you feel full. When you have completed your log, determine how many calories you are consuming and find the average. Then, for a week, take a 100 mg or 200 mg caffeine pill, depending on your body weight and individual sensitivity to the drug, 15 minutes before you sit down at the table. Keep the same record as you did in the previous week. Again, don’t try to force yourself to eat less. Eat until you feel satisfied. Then, at the end of the week, calculate your average calories per lunch and compare your two logs. Were your portions smaller? Did you have fewer side dishes? Were you able to skip deserts? And, most important, was the average calorie count reduced during the week you were taking caffeine?
Don’t forget that everyone has a different caffeine sensitivity level. Only by trial and error can you determine how much caffeine you should use to achieve a weight loss benefit from the drug. If you take caffeine before your meal, you may want to drink decaf coffee after your meal, to get a weight loss benefit while keeping your total intake of caffeine the same.
Also you don’t have to take caffeine before every meal. It’s not all or nothing. Depending on your needs and dietary habits, you might want to use caffeine only on special occasions. For example, if you are on a diet and are planning to attend a lavish buffet lunch, and you know that you usually succumb to the temptation to take large portions and go back for second or even third helpings, you might want to take caffeine before this affair. Or you might be unable to use caffeine as an appetite suppressant before dinner, because dinner time occurs after your personal caffeine cut off point, and it would therefore interfere with getting a good night’s sleep. One approach is to remember that, if taken before breakfast, caffeine may work to suppress your appetite for the entire day.
The beauty of using caffeine to suppress your appetite is that you can eat less and still feel that you enjoyed a complete meal. You don’t have to go hungry. As we said, many stimulants, including amphetamines and cocaine, can accomplish the same thing. But the other stimulants are not only illegal; they are dangerous to your health.
Increasing Your Metabolic Rate
Many books have been written to unravel the supposed mystery and complication that surrounds the question of what makes people gain weight and how they can lose it. The basic truth, however, is simple: The amount of weight you gain is proportional to the difference between the number of calories you take in and the number of calories you burn. For every 3500 calories you take in and fail to burn, you will gain one pound. Conversely, every time you burn off 3500 calories without increasing the amount of food you take in, you will lose one pound. Simple arithmetic shows that if you are consistently taking in 100 calories a day more than you are burning, you will gain 10 pounds a year.
You burn calories by doing exercise and doing work. But you also burn calories simply by being alive, breathing, circulating your blood, and keeping warm. The speed at which you burn calories in this way is a function of your basal metabolism. The faster your basal metabolism, the more quickly you burn calories. We all know people with fast metabolisms—they’re the ones who seem to stay thin their whole lives no matter how much they eat.
As we mentioned above, the amount of weight you lose or gain depends upon the difference between the number of calories you take in by eating and the number of calories you burn throughout the day. Calories are burned in three basic ways. First, there is your basal metabolism, accounting for about 50 to 75 percent, which means the energy you consume just by being alive, without using any calories to move about. Second, there is digestion, accounting for about 10 percent, which is the energy you consume when you are processing your food. Third, there is physical activity, accounting for about 15 to 40 percent, which includes all activities, from walking to your refrigerator to swimming a 1500 meter race. From this analysis, it is obvious that if you could increase your basal metabolism by 10 to 20 percent, you would be burning between 5 and 15 percent more calories overall.[v]
Your basal metabolic rate is initially determined by genetic factors. However, your actual metabolic rate at any given time can be influenced by many things. For example, if you are deprived of food for a prolonged period, your metabolic rate will slow down. Conversely, if you are briefly exposed to a cold climate, your metabolic rate will increase to help keep you warm.
Caffeine increases your metabolic rate, which in turn causes you to burn more calories, and therefore to tend to lose weight. Even if it only increases your metabolism by 5%, this is enough to make the difference between being fat and being thin! According to researcher Robert Conlee, PhD, caffeine increases the metabolic rate through its effects on the neurotransmitter systems, “Caffeine increases the metabolic rate of muscle, either directly or indirectly, through release of catecholamines.” In fact, caffeine, as many studies have proven, will speed up your metabolism for 24 hours after ingestion.[vi], [vii], [viii]
Small increases in metabolic rate cause the body to release energy as body heat instead of converting it into body fat. Even when the differences in energy expenditure are so slight that they are difficult to measure, explains Cornel nutritional biochemist T. Colin Campbell, they can make a big difference in your weight over time. As little as 50 to 100 calories a day in a 2,500 calorie diet, “if unburned…can add up to 10 additional pounds a year.”[ix]
A similar conclusion was reached in a peer reviewed article about caffeine published in the Navy Health Book in 1997, in which a Navy researcher states, “Caffeine, at doses equivalent to one cup of coffee, raises the metabolic rate slightly for a couple of hours. If a person wanting to lose weight could refrain from making up this energy deficit with food, these small changes in the metabolic rate (75-100 calories/day) could lead to a substantial weight loss.”[x]
Research suggests that, on the average, 200 mg of caffeine will speed up your metabolism by about 15% for about two or three hours. If you took this dose of caffeine three times a day, the total increase would result in burning about 75 to 100 calories more than you would have otherwise burned. It may not seem like much, but, as we said above, a difference of 100 calories a day results in a net difference in weight of 10 pounds a year. After a few years, a difference like that would really begin to add up!
Most of us already consume more than one cup of coffee a day, and the metabolic benefits of that amount of coffee have been compensated for by our diet. Without consciously deciding to do so, we allow ourselves to eat a little more than we would otherwise have because we can do so without putting on any additional weight. Therefore, to capitalize on the metabolism-increasing and fat-burning benefits of caffeine, we must increase the total amount of caffeine we are taking on a daily basis.
This can be done by taking a caffeine pill before lunch while continuing to consume your regular cup of coffee or tea after your lunch. This additional caffeine before the meal may be enough to help you lose weight by increasing your metabolic rate. If you are increasing the amount of caffeine you are taking by doing this, you may want to drink decaf during your afternoon coffee breaks to limit your total intake. Otherwise your total caffeine intake may be higher than you’d be comfortable with.
One final note on metabolism. When you’re fatigued, your metabolic rate slows. In addition to restoring your energy and brightening your mood, caffeine actually boosts your metabolism up to the levels of a well-rested person.[xi]
Increasing Fat Burning and the Benefits of Exercise
In addition to reducing your appetite and increasing your metabolism, caffeine can help you lose weight by increasing lipolysis, or fat burning, especially when you are exercising. This means that caffeine literally helps to speed up the rate at which fat is eliminated from your body. In one study trained male and female cyclists were instructed to perform two hours of cycle exercise to produce the greatest amount of work possible. Those who had ingested two doses of 250 mg of caffeine (one taken before and one during the exercise) burned 31% more fat than those who did not take caffeine before and during cycling! They also expended about 7.5% more energy.[xii]
Whether we are at rest or working out, caffeine increases fat burning by increasing the release of catecholamine neurotransmitters, including dopamine and epinephrine, which activate the enzymes, or biological catalysts, “responsible for lipolysis in muscle and adipose tissue.”[xiii]In other words, caffeine tells your body to burn fat!
Caffeine and Cellulite: Can Caffeine Actually Melt Away Fat on Your Thighs?
It has long been known that caffeine and closely related compounds, such as aminophylline, literally cause cells to burn fat. As long ago as 1985, scientists Frank L. Greenway of UCLA and George A. Bray, MD, of the Pennington Biomedical Research Center at Louisiana State University, patented an anti-cellulite cream based on aminophylline.
Very little was known about the composition of anti-cellulite creams by the dermatological community until a 2000 article in the European Journal of Dermatology examined 32 anti-cellulite products, containing 44 different emollients and 39 different botanicals. Caffeine, present in fourteen of these anti-cellulite products, was the most common additive.[xiv] Neutrogena, for example, makes one of them. The study found that all the creams were microbiologically pure and concluded, “In spite of the large number of substances used in cellulite creams, their safety seems acceptable for most users.” Do they work to reduce cellulite? Well, that’s another matter!
David Heber, a professor of medicine and chief of clinical nutrition at UCLA explains that, if you put fat cells in a culture dish with caffeine, “you can literally watch them release their stores of fat.” The question remains, however, if these creams really deliver a substantial practical benefit in actual use. One study found that even after six weeks of application, in which women used the cream on only one thigh, they lost less than a half inch from thighs treated with the creams as compared with untreated thighs. However, there is anecdotal evidence that these creams can have at least a temporary effect that is significant. Some models apply them before photo shoots to help shrink their thighs.
When taken before exercise, caffeine also has the specific ability to burn off the fat stored in the viscera, the soft internal organs of the body, including the intestines and those contained within the abdominal and thoracic cavities. Although you can’t see such fat deposits from the outside, high levels of fatty build up in these organs is bad for your health. By taking caffeine before exercise, we potentiate the fat-burning effects of exercise in these areas of the body. Scientists suggest that such effects on “visceral adipocytes,” or fat cells in internal organs, can boost insulin sensitivity as well.[xv]
Caffeine is metabolized, or transformed, by the body largely into a related chemical called “paraxanthine.” Scientists have shown that the activity of paraxanthine is directly responsible for the increase in lipolysis that occurs after caffeine ingestion. As caffeine is metabolized and paraxanthine is formed, there is a simultaneous increase in free fatty acid levels, indicating that paraxanthine is an “active lipolytic agent,” that is, something that facilitates the burning of fat. Once again, caffeine’s effects on the adenosine neurotransmitter system seem to be the key to how it accomplishes this. Caffeine and its metabolites, including paraxanthine, increase fat burning primarily by blocking adenosine receptors on the surface of fat cells.[xvi]
Although caffeine in large enough doses does increase adrenaline, studies indicate that this is not the primary way that caffeine increases the amount of fat we burn and that increases in fat-burning occur even when adrenalin levels are kept constant. As we state above, caffeine acts directly on fat cells to cause them to shrink!
Everyone knows that, if you want to lose weight, it is important, even necessary, to get more exercise. One of the remarkable benefits of caffeine is that caffeine increases your ability to walk, run, and participate in sporting activities by boosting your endurance, your speed, and even by instilling an “attitude of success.” What this means is that by using caffeine, you will be able to exercise longer and harder and, what is more, that you will look forward to doing so. There are no double-blind studies of exactly how many more pounds you will lose as a result. But it is certain that, even if caffeine had no other weight loss benefit apart from increasing the amount and quality of your exercise, it would be an immensely valuable tool in the fight to become and stay slim.
What difference will increasing your level of exercise make to how much weight you lose? For many people, the difference between being slender and fat is as small as 50 to 100 calories a day. As we explain above, 100 calories a day make a net difference in your weight of 10 lbs a year. If you increase your level of exercise—or even your overall activity level—even slightly, and boost your caloric expenditures in this way, you should experience a significant weight loss over time.
One good idea is to take 100mg to 200 mg of caffeine, depending on your weight and your individual sensitivity to the drug, 15 minutes or longer before doing an early morning workout on a treadmill or stationary bicycle or even to try some calisthenics or weight lifting. Taking this dose of caffeine will help you to work out longer and harder, thus helping you to lose more weight. If you feel no problems taking 200mg, you may want to try increasing your dose to 300mg or even more. Because you are taking it early in the morning, it probably won’t keep you awake at night.
The Four Ways Caffeine Works to Help You Lose Weight
- Decreases your appetite and makes you feel full faster and keeps you feeling full longer;
- Increases lipolysis, or fat burning;
- Increases your basal metabolic rate, thus burning calories instead of storing them;
- Increases your ability to exercise and the amount of energy you expend and the amount of fat you burn when you do exercise.
[i] Sophie D and Michael D Coe, The True History of Chocolate, London: Thames and Hudson, 1996, p. 51.
[ii] Miriam E. Nelson, Ph.D., and Sarah Wernick, Ph.D., Strong Women Stay Slim, Bantam Books, New York, 1998, p. 31-32.
[iii] Miriam E. Nelson, Ph.D., and Sarah Wernick, Ph.D., Strong Women Stay Slim, Bantam Books, New York, 1998, p. 31.
[iv] Andersen, T, and J Fogh, “Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients,” Journal of Human Nutrition & Dietetics, 14(3):243-50, 2001 June.
[v] Miriam E. Nelson, Ph.D., and Sarah Wernick, Ph.D., Strong Women Stay Slim, Bantam Books, New York, 1998, p. 22.
[vi] Astrup, A., et al, “Caffeine: A double-blind, placebo-controlled study of its thermogenic, metabolic, and cardiovascular effects in healthy volunteers, American Journal of Clinical Nutrition, 1990; 51:759-767.
[vii] Horton, TJ, CA Geissler, “Post-prandial thermogenesis with ephedrine, caffeine, and aspirin in lean, pre-disposed obese and obese women,” International Journal of Obesity, 1996; 20:91-97.
[viii] TE Graham, et al, “Caffeine and Exercise: Metabolism and Performance,” Canadian Journal of Applied Physiology, 1994: 19;111-138.
[ix] “Turkey, gravy, and thermogenesis: Low-protein and low-fat diet keeps pounds off the waistline and increases desire to exercise,” Cornell University press release, November23,1998, contact Roger Segelken.
[xi] Bonnet, M.H., and the amount of energy you expend and the amount of fat you burn when you do exercise.
DL Arand, “Metabolic rate and the restorative function of sleep,” Physio. Behav, 59, 777, 1996; See also Van Cauter studies.
[xii] Ivy, J.L., et al, “Influence of caffeine and carbohydrate feedings on endurance performance,” Med Sci Sports 1979; 11: 6-11.
[xiii] Conlee, Robert K., “Amphetamine, Caffeine, and Cocaine,” in Ergogenics: Enhancement of Performance in Exercise and Sport, DR Lamb and MH Williams, ed,, Indianapolis: Brown and Benchmark, 1991
[xiv] EL Sainio, et al, “Ingredients and safety of cellulite creams,” European Journal of Dermatology, 10(8):596-603, 2000 Dec.
[xv] MF McCarty, “Modulation of adipocyte lipoprotein lipase expression as a strategy for preventing or treating visceral obesity,” Medical Hypotheses, 57(2):192-200, 2001 Aug
[xvi] Hetzler, RK, et al, “Effect of paraxanthine on FFA mobilization after intravenous caffeine administration in humans,” Journal of Applied Physiology, 68(1):44-47,1990.