Caffeine is widely used in sports as part of energy drinks and fat burners. It is a strong stimulant of the nervous system, having a systemic effect on the body, including fat-burning.
In this article, we will examine the properties of caffeine and scientific research on its benefits for weight loss.
Main thoughts:
Products high in caffeine: coffee, tea, cocoa, chocolate, mate tea
Scientific studies do not confirm the appetite-suppressing effect of caffeine
Properties of Caffeine
Caffeine is a stimulant substance that is used in energy drinks (to increase physical performance) and as an ingredient in fat burners (for weight loss).
Caffeine was originally discovered in coffee beans, and today it can also be synthesized in the laboratory.
The active ingredient in coffee, energy drinks, tea, and fat burners is the same substance, with an identical chemical formula.
According to classification, caffeine belongs to the class of nootropic substances (nootropics are substances that act directly on the brain) as it increases the sensitivity of neurons in the brain and stimulates brain activity, enhancing attention and alertness.
Properties of caffeine:
- In sports, caffeine is used to increase physical strength and endurance;
- Scientific research confirms the benefits of caffeine for weight loss;
- Caffeine causes systemic vasoconstriction and an increase in blood pressure, more pronounced in those whose bodies are not accustomed to its consumption;
- Caffeine is effective in combating sleep; it also affects its quality: you may fall asleep, but you are unlikely to feel rested;
- Regular caffeine intake reduces the risk of developing Alzheimer’s disease, cirrhosis, and liver cancer;
- Regular use of caffeine leads to tolerance, with the almost complete disappearance of its characteristic “beneficial” effects (except for combating sleep). Increasing the dose does not help. A break from consumption for a month can restore sensitivity.
Caffeine is a very strong stimulant that causes systemic vasoconstriction throughout the body. Be cautious with its use if you have high blood pressure or if you are just starting to experiment with this supplement. If you have any heart problems, be sure to consult a doctor before starting to take it.
Caffeine is a natural stimulant of the nervous system, belonging to the class of nootropics that act directly on the brain
What contains caffeine?
The highest amounts of caffeine are found in the following natural products:
- coffee;
- tea (green, black);
- cocoa;
- chocolate;
- guarana;
- mate tea;
- kola nut.
Until recently, coffee and tea accounted for over 90% of caffeine consumption in our society, with the remaining 10% belonging to cocoa products (such as chocolate).
With the emergence of energy drinks and carbonated beverages containing caffeine, they have taken about 12% of the market for caffeine-containing products, while the share of coffee and tea has decreased to 83% 1-3.
Today, caffeine is the most popular legal stimulant worldwide. In America, about 90% of the population consumes it in one form or another.
The average dosage per person is 190 mg per day. In European countries, the consumption level is even higher (mainly due to a more developed coffee culture) – over 300 mg per person per day.
As for the main sources of caffeine (tea and coffee), the exact content of caffeine in them is a variable quantity.
– How much caffeine is in coffee?
The amount of caffeine in coffee varies between 40-180 mg per 150 ml, depending on the type of beverage 2.
– How much caffeine is in tea?
The amount of caffeine in tea is also not fixed and ranges from 24-50 mg per 150 ml 2.
– How much caffeine is in cocoa?
The mass fraction of caffeine in cocoa is about 0.21%, while finished chocolate products contain about 0.017-0.125% caffeine by mass. Commercial hot chocolate, for example, may contain 4-5 mg of caffeine per serving.
Products with high caffeine content: coffee, tea, cocoa, chocolate, mate tea
Scientific research on the benefits of caffeine for weight loss
Caffeine is one of the most well-known fat burners, the effectiveness of which for weight loss is confirmed by numerous scientific studies.
However, whenever we talk about fat burners, a more relevant question is not about the effectiveness per se, but about the degree of effectiveness.
Remember the general principle: the effect of taking any fat burner, even the strongest one, amounts to just a few hundred kilocalories a day (200-300 kcal). This can be achieved by making light and painless adjustments to your diet. At the same time, increasing the dose in an attempt to “burn” more fat significantly increases the risk of harm to your health.
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1 Caffeine accelerates internal metabolism
As is known, the lion’s share of calories that our body burns throughout the day is spent on maintaining internal metabolism, and therefore the most effective strategy for weight loss is to increase the speed of internal metabolism. We discussed this in the article The main cause of obesity or Why only physical exercises are useless for weight loss.
It is through this mechanism that caffeine acts as a fat burner.
Experiment: The effect of coffee consumption on metabolic rate (= fat burning) in women suffering from obesity
The positive effect of caffeine on metabolic rate was demonstrated in an experiment involving women suffering from obesity, who experienced varying degrees of an increase in metabolic rate for several hours after taking a dose of caffeine at 4 mg/kg 30 minutes later.
According to scientists, such a spike can indeed be beneficial for weight loss, especially in combination with a low-calorie diet 6.
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In this study, after 2 months of the experiment, the body weight and fat mass in women significantly decreased (on average by 4 kg).
The dose of caffeine at 4 mg/kg used in the experiment is equivalent to approximately 3 cups of coffee.
Scientists even provide a mathematical calculation of how many calories are burned when consuming 3 cups of coffee (4 mg/kg of caffeine): at this dosage, approximately 8 kcal per hour is burned for each square meter of a person’s body surface.
For an average person, the body surface area is about 1.73 m2, which means that by drinking 3 cups of coffee, they will burn approximately 14 kcal per hour. Another study cites a figure of 32 kcal/hour at a higher dose of 400 mg (5.5 mg/kg) 8.
The authors of this study note that the effect of caffeine consumption on weight loss significantly depends on the dosage 9.
However, it is very important to note that in this study, the subjects, in addition to consuming caffeine, adhered to a low-calorie diet and performed physical exercises – factors that are sufficient conditions for weight loss on their own.
Experiment: The Effect of Caffeine on the Internal Metabolic Rate in Athletes and Sedentary Individuals
When it comes to athletes and sedentary individuals, the results of scientific studies on the effect of caffeine on their metabolism are contradictory.
In one of them, professional athletes (marathon runners, cross-country skiers) took 4 mg/kg of caffeine (an average of 280 mg). As a result, it was shown that caffeine significantly increased their metabolic rate compared to sedentary individuals 10.
However, another study using 300 mg of caffeine showed opposite results: even sedentary individuals had a higher metabolic rate 11.
The Fat-Burning Effect of Caffeine Disappears with Prolonged Use
The increase in metabolic rate, and thus the effectiveness of caffeine for weight loss, is a well-established fact. However, with prolonged use, the fat-burning or stimulating effect decreases or may even disappear entirely.
Scientists found that taking caffeine for 24 weeks at a dose of 200 mg did not lead to fat loss, nor did 100 mg of caffeine over 16 months along with 20 g of fiber 12,13.
(In this same study, it was shown that carbohydrate restriction in the diet is less effective for weight loss than fat restriction).
Another study, which consisted of a 4-week low-calorie weight loss phase and a 3-month maintenance phase (during both phases, green tea and caffeine were consumed), showed that caffeine consumption was associated with greater weight loss in the first phase and had no effect on fat mass in the second phase 14.
Caffeine can stimulate the rate of internal metabolism and, as a result, be beneficial for fat burning; however, its effectiveness diminishes with habituation. The best way to consume caffeine for weight loss is to alternate phases of intake and abstinence along with calorie restriction in the diet.
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2 Caffeine reduces appetite
Appetite suppression is another mechanism of action for some fat burners: you feel less hungry, fewer calories are consumed, resulting in weight loss.
The appetite-suppressing effect of caffeine has been noted by scientists in experiments on rats, but human studies DO NOT confirm its effectiveness in this regard.
In several of them, no appetite-suppressing effect of caffeine was observed when consumed at a dose of 3 mg/kg body weight by men, and in another study, when 300 mg of caffeine was consumed by women 16,17.
Scientific research does not confirm the benefits of caffeine for weight loss in terms of appetite suppression.
3 Caffeine and ephedrine: together more effective for weight loss than separately
Scientific data suggest that the combination of caffeine and ephedrine has a stronger fat-burning effect.
Several studies have shown the effectiveness for weight loss and appetite suppression of dosages of ephedrine and caffeine 25 mg / 200 mg, three times a day.
Note that this refers specifically to ephedrine, not the plant ephedra from which it is derived, which may be more dangerous to health.
The combined fat-burning effect of caffeine with ephedrine is approximately 64% greater than what could be expected if the calories burned from taking both substances separately were simply added together 18.
The combination of these two substances significantly increases adrenaline levels more than either one alone; accordingly, the benefits (stimulatory effect, appetite suppression, fat burning) also increase, as do the potential negative side effects 19.
Ephedrine and caffeine have a significantly more pronounced fat-burning effect. The effectiveness for weight loss and appetite suppression of dosages of ephedrine and caffeine 25 mg : 200 mg, three times a day has been demonstrated.
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How to take caffeine for weight loss? Dosage
The following recommendations for caffeine use are provided by researchers from the Examine.com portal based on the study of scientific experiments.
Ideally, the dosage of caffeine should be calculated individually, depending on the goals.
For those who are “just starting,” it is recommended to take no more than 100 mg per day; higher doses will lead to an increase in blood pressure for several hours (~4 hours). As you get used to it, the problem will disappear.
To achieve a fat-burning effect, the recommended dose of caffeine should be at least 200 mg per day (this amount is present in most fat burners based on it).
In sports energy drinks, the caffeine content can reach 500 mg per can, but on average it is 100-200 mg.
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When it comes to individual dosage calculation, scientific studies on the benefits of caffeine for weight loss generally follow the rule of 4-6 mg per kg of body weight.
Caffeine is usually taken in the form of popular beverages containing it (coffee, tea, energy drinks), as well as dietary supplements in the form of tablets (read below about their differences).
How to properly take caffeine to avoid habituation?
With prolonged use, most of the effects characteristic of caffeine (fat burning, energy stimulation, euphoria) disappear; increasing the dosage does not help to bring them back.
To restore the positive effects, scientists recommend taking breaks from caffeine when effectiveness decreases for some time, followed by resumption.
It is better to start taking caffeine with small doses. A typical weight loss dose of caffeine is 200 mg, while energy drinks contain 500 mg or more. When habituation develops, take breaks.
