Can Coffee boost your metabolism and help you burn more fat?
Coffee contains caffeine, which is the most commonly consumed psychoactive substance in the world.
Caffeine is also included in most commercial fat-burning supplements today — and for good reason.
It's one of the few substances known to help mobilize fats from your fat tissues and increase metabolism.
But does coffee really help you lose weight?
Many biologically active substances found in coffee beans find their way into the finished product.
Several of them can affect metabolism:
Caffeine: The main stimulant in coffee.
Theobromine: The main stimulant in cocoa; also found in smaller amounts in coffee.
Theophylline: Another stimulant found in both cocoa and coffee; has been used to treat asthma.
Chlorogenic acid: One of the main biologically active compounds in coffee; may help slow the absorption of carbs.
The most important of these is caffeine, which is very potent and has been studied thoroughly.
Caffeine works by blocking an inhibitory neurotransmitter called adenosine.
By blocking adenosine, caffeine increases the firing of neurons and release of neurotransmitters like dopamine and norepinephrine. This, in turn, makes you feel more energized and awake.
In this way, coffee helps you stay active when you would otherwise feel tired.
Caffeine stimulates the nervous system, which sends direct signals to the fat cells, telling them to break down fat. It does this by increasing blood levels of the hormone epinephrine.
Epinephrine, also known as adrenaline, travels through your blood to the fat tissues, signalling them to break down fats and release them into your blood.
Of course, releasing fatty acids into your blood does not help you lose fat unless you are burning more calories than you consume through your diet. This condition is known as a negative energy balance.
You can reach a negative energy balance by either eating less or exercising more. Another complementary strategy is to take fat-burning supplements such as caffeine.
The main lesson to learn
In the short term, caffeine can boost the metabolic rate and increase fat burning, but after a while people become tolerant to the effects and it stops working.
But even if coffee doesn’t make you expend more calories in the long term, there is still a possibility that it blunts appetite and helps you eat less.
In one study, caffeine had an appetite-reducing effect in men, but not in women, making them eat less at a meal following caffeine consumption. However, another study showed no effect for men.
Whether coffee or caffeine can help you lose weight in the long term may depend on the individual and there general health, diet and lifestyle.