Does Coffee Really Help In Losing Weight?

Coffee, coffee and more coffee! I could probably go to extraordinary lengths just for that one whiff of coffee aroma. Yep I am a coffee lover or addict, however you like it and I just don’t seem to get enough of it.

As usual, science talks about coffee’s rich antioxidant profile and at the same time claims that its consumption increases susceptibility to osteoporosis.

But that’s the regular whirlwind ongoing in the research field. And also in the field of nutrition!

People say that coffee causing weight loss is a myth and some swear about its anti-obesity action. So we decided to put up investigating feelers and dig up some stuff. Here is what we have to share.

What makes coffee so special?

Coffee is prepared from roasted coffee beans of the Coffea plant.  Among the 80 varieties of coffee available, only two varieties are popular in the market: Arabica coffee and Robusta coffee.

Green coffee seeds are obtained from coffee fruits after the pulp has been removed. Three components that impart flavour and aroma to coffee are:

  • Caffeine:  It a nervous stimulant and widely consumed psychoactive substance. It accounts for 10% of the perceived bitterness of the beverage.
  • Trigonelline: It contributes to bitterness of the brew and is said to improve memory and serves as a phytoestrogen.
  • Chlorogenic acids: They are present in high amounts in green coffee and impart acidity, astringency and bitterness to the brew. They possess anti-obesity property.

However with roasting, chlorogenic acid content is reduced to around 1% of original concentration. Caffeine on the other hand remains unaltered despite of roasting.

So when you are looking up to coffee as a weight loss guide, its caffeine content is of due importance:

  • Cafetiere: 100mg caffeine per cup
  • Filter: 100-150 mg caffeine
  • Espresso: 80mg caffeine
  • Instant: 65mg caffeine
  • Percolated: 80-100mg caffeine
  • Turkish:  160mg caffeine
  • Cappuccino: 80mg caffeine
  • Decaffeinated coffee: 1-2g/100g

Apart from that coffee is rich in antioxidants, minerals and vitamins especially vitamin B.

How does coffee help with weight loss?

Here is what research has to say about coffee’s effect n weight and body fat loss.

1.Coffee boosts metabolism

Four clinical trials  were conducted to assess the effect of coffee and caffeine on metabolism. In the first trial 8mg/kg of caffeine was given to normal weight volunteers. Metabolic rate increased significantly after 3 hours of consumption and oxidation of fats was also observed.

coffee image 1Coffee was more effective than decaffeinated coffee in initiating thermogenesis after the meal and fat oxidation also occurred.

Researchers concluded that coffee raises metabolism in normal and overweight subjects but it caused fat oxidation only in normal weight individuals.

In another clinical trial  participants were given 150 ml decaffeinated coffee with or without 200mg added caffeine. Caffeine consumption brought about a 7% increase in energy expenditure which lasted for  hours.

What does this mean?
Coffee elevates metabolic rates which means that it increases your potential to burn calories. And its the caffeine that makes the difference.

2.Caffeine prevents accumulation of fats

An animal study  was conducted to investigate the effects of bioactive constituents of tea, one of them being caffeine, on preventing fat accumulation. Mice were fed diets containing these bioactive constituents for 4 weeks.

It was found that these constituents inclusive of caffeine interfere with fat metabolism in the liver. They lower the activity of fat synthesizing enzymes and increase the activity of antioxidant enzyme.

Apart from having its implications in obesity, this property of caffeine and other related compounds can be used in treatment of fatty liver disease.

Another mechanism by which caffeine prevents accumulation of fats is by increasing levels of catecholamines.   Catecholamines are fight and flight hormones. They are released in response to stress.

Ephinephrine, norepinephrine and dopamine constitute catecholamines. These hormones stimulate breakdown of fats to a state where they are utilised as a source of energy.

What does this mean?
Caffeine prevents fat from being deposited by interfering in fat metabolism in the liver and elevating levels of hormones that metabolize fats.

3.Caffeine prevents development of fat cells

A lab study  investigated the effect of caffeine on development of fat cells based on the idea that caffeine consumption leads to loss of weight and interferes with fat metabolism.  Stem cells were exposed to caffeine during developmental stages.

Caffeine inhibited differentiation of the stem cells into fat cells by 20-50%.It also decreased the activity of the genes that support development of fat cells and tissue.

This is an interesting piece of information but whether the same mechanism is followed in our body is still a thought.

What does this mean?
Apart from preventing fat deposition, caffeine prevents development of fat cells in the first place.

4.Caffeine activates brown fat

We have two types of fat in our body: brown fat and white fat. White fat tissue stores fat while brown fat tissue burns fat to maintain body temperature. Activation of brown fat leads to weight loss.

An animal study  demonstrates that caffeine injection results in binding of caffeine to biological indicator of brown fat activity and stimulates burning of fat and increase in temperature of brown fat tissue.

What does this mean?
Caffeine activates brown fat in order to burn fat and energy.

5.Coffee influences hunger and appetite

In this study  volunteers were given breakfast along with 200 ml of coffee containing 3 or 6mg of caffeine/kg body weight or water. 3 hours after consumption of the beverage they were given an unrestricted meal.

Reduced energy intake was seen at the subsequent meal and also throughout the day in coffee consumers. Also the coffee with higher caffeine concentration was found to be more effective in controlling appetite.

In another study , with similar arrangements, it was found that decaffeinated coffee resulted in lower hunger rating and increased levels of satiety hormone-peptide YY . (To learn more about PYY and other appetite suppressants read what are appetite suppressants?)

Interestingly caffeinated coffee was slightly less potent in controlling appetite.

A clinical trial  was conducted wherein individuals were given placebo, decaffeinated coffee, caffeine or caffeine with decaffeinated coffee. They were also given breakfast and four and half hours after breakfast they were given access to an unrestricted meal.

Energy intake was found to be similar in all groups and no significant difference was observed in terms of appetite and gastric emptying. Another study also reported similar results.

These results are indeed confusing but those who are habitual coffee consumers definitely feel content at least for a short term after consuming coffee.

What does this mean?
Coffee controls appetite and lowers hunger for short term. There is no preference of decaf or caffeinated coffee with regards to this.

6.Coffee improves gut microbes

Coffee is absorbed in stomach and small intestine and further fermented in the small intestine by the microbes present there.  A study  was conducted where rats fed with high fat diet were given caffeinated coffee for 10 weeks.

Coffee was found to decrease body weight and body fat as well as energy intake. In addition it was observed that coffee decreased the number of unhealthy microbes and promoted the growth of healthy microbes.

Researchers concluded that coffee consumption improves gut microbe that is disturbed by high fat diet.  Healthy gut microbes prevent absorption of excess fat from diet and aid in fat metabolism.

What does this mean?
Coffee ameliorates damage to intestinal microflora caused by high fat diet.

7.Caffeine enhances exercise performance

Caffeine is used widely as an ergogenic aid. It enhances exercise performance by providing boost of energy. And as per the studies this energy is not derived from glycogen stored in muscles or circulating glucose but instead this comes from mobilization of fats from fat tissue.

One study clearly showed that the levels of free fatty acids in the blood increased after caffeine ingestion during exercise.  When given in combination with carbohydrate, caffeine stimulated the use of fat as an energy source rather than carbohydrate.

Another study demonstrated that caffeine ingestion increased exercise performance by increasing metabolism and stimulating fat oxidation.

What does this mean?
Coffee provides a great deal of energy which enhances exercise performance and better exercise means more weight loss.

Coffee featured image

8.High caffeine intake is associated with lower BMI

In a study  investigating the effect of green tea enriched with caffeine on body weight, the relationship between caffeine intake and weight was also studied. It was observed that high caffeine consumers reduced weight, fat mass and waist circumference more than low caffeine consumers.

Researchers felt this association was primarily due to coffee’s effect of increasing metabolism, oxidising fat and suppressing leptin levels. Leptin is a satiety hormone but its level is proportional to fat levels in obese individuals in which case leptin resistance develops.

In a study  investigating prevalence of metabolic syndrome in coffee and tea consumers, it was observed that high coffee consumers, thats 3 or more cups a day, had lower BMI, waist circumference, blood pressure and cholesterol than those who consume one cup a day.

What does this mean?
High coffee consumers tend to have lower body weight and waist circumferences.

9.Caffeine and epehedra: a weight loss duo

Caffeine and ephedra combination is sold widely as a weight loss supplement. Epehedra is a medicinal preparation from plant Ephedra sinica.  It contains ephedrine which acts stimulant. One study reports that this combination increases metabolism by 8% and favors weight and fat loss.  It does not cause any cardiovascular side effects.

A 6 month clinical trial  demonstrated that caffeine/ephedra caused a weight loss of around 5 kg and fat loss of 4kg with little but tolerable side effects. Caffeine and ephedra are as good as leptin in lowering body weight and visceral fat.

A 15 week trial  demonstrated the combination is better than dexfenfluramine in mediating weight loss. Dexfenfluramine and leptin are appetite suppressants.

What does this mean?
Research validates the use of caffeine and ephedra as weight loss supplements. However use of ephedra has been prohibited in weight loss supplements due to health risks associated with it.

10.Sugar derived from coffee helps lose weight

Manooligosaccharides (a complex term for sugar) extracted from coffee is said to decrease body fat. A 12 week clinical trial  was conducted wherein beverages containing 4g of this compound were given to the volunteers.

Men consuming this beverage experienced greater weight loss especially of subcutaneous (fat present below the skin) and visceral fat. Oddly women did not experience such substantial weight loss.

Researchers concluded that such coffee derived monooligosaccharide can be used for weight management.

What does this mean?
Sugar like compounds derived from coffee are said to have weight loss potential.

11.Innovative weight loss beverage based on coffee silverskin

Coffee silverskin is the coating that surrounds the coffee bean once the pulp has been removed. It is a major waste product of coffee roasting industry.

Research  suggests that coffee silverskin can be used a bioactive extract to design a weight loss beverage. This beverage is proposed to contain caffeine and chlorogenic acid in amounts at which they can aid in burning fat and also add flavour to the beverage.

This antioxidant rich beverage is thought to be an innovative way of targeting weight loss and making good use of coffee by product.

What does this mean?
Coffee silverskin is a waste product of coffee industry. Research apparently claims that this silverskin can prove to be a great extract for designing weight loss beverage.

12.Caffeine prevents weight regain during weight maintenance

Calorie shifting diet is consuming different amounts of calories each day in order to elevate the body’s metabolism.
In this study  obese female subjects were kept on a calorie shifting diet for 6 weeks (3 repeated phases) and 4 weeks follow up diet, both with or without caffeine.

Significant weight and fat loss was seen with calorie shifting diet (5.7 Kg and 4.84Kg) which was accelerated with caffeine treatment (7.57 Kg and 5.24 Kg).

This effect was persistent for 1 month of follow up where weight loss with caffeine and calorie shifting diet was approximately 12kg and fat loss was 9kg. In addition it was found that coffee increased the effect calorie shifting diet on hunger control and satiety.

What does this mean?
Caffeine increases weight loss outcomes of a calorie shifting diet and even aids in keeping the kilos off during weight maintenance.

What is green coffee bean?

Green coffee bean is nothing but unroasted coffee bean. Its extract is marketed as a popular weight loss supplement. Caffeine and chlorogenic acid are two components of green coffee bean extract that confer to it the anti-obesity property.

It is said to aid in weight loss but boosting metabolism and burning fat. To know more about green coffee bean read: Green coffee bean& weight loss.

Health benefits of coffee

There are a number of reasons why you should drink coffee, apart from the weight loss factor:

  • It provides a great boost of energy and increases your exercise performance.
  • It provides a rich source of antioxidants.
  • It lowers the risk of neurodegenerative diseases like Alzheimer’s and Parkinson’s.
  • It lowers cholesterol and protects liver from damage by fats.
  • It lowers risk of some type of cancers.
  • It protects from cardiovascular diseases.

Dosage

If you are planning on making it a regular habit, I would not recommend more than 3 cups of coffee per day even if there are a million health benefits attached to it.

A dose of 100-200mg of caffeine increases alertness, focus and body coordination. A limit of 400mg should be maintained which is around four cups. For increasing exercise performance a dose of 3-6mg/kg body weight is permitted.

Instant coffee has lower caffeine and chlorogenic acid compared to drip coffee. So it is preferable to have drip coffee. Also avoid taking much sugar with your coffee.

Precautions

As mentioned previously, coffee or rather caffeine is a nervous stimulant. If taken in excess it can prove to be hazardous.

It can cause restlessness, anxiety, headache, dizziness.  It can dilate blood vessels and passages of the lung, increase gastric acidity and cause gastrointestinal problems. It is an addictive substance and one can tend to develop withdrawal symptoms after interruption of prolonged use.

Another thing that should be kept in mind is the sugar content of coffee. If you take coffee with a lot of sugar or flavouring syrup it will definitely make you gain weight.

Conclusion

Adequate research proves numerous ways by which coffee and especially caffeine can help burn fat and lose weight. But there is definitely a need for good randomised, blind clinical trials on this aspect so as to boldly confirm the use of coffee for weight loss.

However coffee is a drink whose aroma and flavour should be cherished irrespective of the health perks. Start with a cup or two of coffee and see if you find any difference within a month’s time.

And make it a point not to try any other weight loss experiments simultaneously. If you see a difference that’s definitely going to keep you going.

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