CHAPTER 3

Next to protein powders, fat burners are the most sold supplements out there. With the alarming statistics of obesity, the alluring call of these ‘magical’ supplements sent from the heavens is tempting.

But are they worth their price tag?

Do fat burners work?

Let’s find out.

First, allow me to answer what a fat-burner is NOT:

A fat burner is not a product that will help you burn fat even if your nutrition and training are crap. Nothing can outdo a bad diet.

Fat loss comes down to energy balance and how well you can maintain your muscle.

Now, what makes most fat burners flawed and outright funny are the claims of their makers:

These are all important aspects of effective fat loss. But, I'm going to go on a limb here and say that this is more of an attempt to sell you on the idea of a fat burner.

Whether that supplement can actually achieve these claims is either a scientific half-truth or uninvestigated.

A good fat burner is there to achieve 3 main things:

Most of the ingredients, found in the fat burners on the market, are ineffective in these regards. Let’s take a look at a few of the most common ones:

Carnitine

Carnitine is synthesized in the body from the amino acids lysine and methionine. The molecule is involved in fatty acid metabolism.

You can find carnitine in many foods. Red meats such as beef are the best options to add to your diet. Fish and milk are also good sources.

In essence, carnitine transports the chains of fatty acids into the mitochondrial matrix. Thus, allowing the cells to break down fat and get energy from fat reserves.

Carnitine has also been shown to increase endurance in athletes who have taken a 3 or a 4-gram dose before running.

Furthermore, I found a dozen or so studies about carnitine’s effect on fat loss and body composition. Sadly, all of them were either poorly executed or did not show any significant benefit of taking carnitine to speed up fat loss.

From what I’ve researched, I’ve come to the conclusion that carnitine doesn’t seem to have a significant impact on fat loss.

But, it can be useful to boost energy levels and help push through difficult workouts.

Caffeine

Unless you’ve been living under a rock, you’ve probably heard about caffeine. It is one of the most widely-consumed substances in the world and it has been shown to aid in fat loss.

More specifically, caffeine may speed up fat loss by increasing your body’s daily energy expenditure and since fat loss comes down to creating a caloric deficit, this substance can help make sure you’re in one.

Caffeine has other benefits, some of which also impact fat loss directly:

Based on the research so far, caffeine appears to be a well-rounded substance that aids fat loss both directly and indirectly.

But, keep in mind that caffeine is a stimulant and your body can get used to it and build a tolerance, making its effects less pronounced. Also, as a stimulant, caffeine can interfere with your sleep, so it’s a good idea to set a curfew and cut out any caffeine drinks within 7-8 hours of your bedtime.

Also, caffeine can be harmful if you exceed the recommended daily limit.

Garcinia Cambogia

Garcinia Cambogia is a bright-green tropical fruit that looks like a small pumpkin. The fruit has been used to flavor Asian and Indian curries.

But what makes the fruit interesting aren’t its citrus-like properties but one of the ingredients it has – hydroxycitric acid (HCA).

HCA has been praised to be a fat-burning agent that raises the levels of the brain chemical serotonin, making you feel less hungry. It also blocks an enzyme called citrate lyase, which your body uses to make fat.

But, despite these claims and the hype, Garcinia Cambogia has failed to deliver.

A meta-analysis of 12 randomized, double blinded clinical trials on garcinia cambogia found that the differences between the groups that took either HCA or placebo were small and insignificant for weight and fat loss.

Furthermore, this study which involved 135 participants came out with the same verdict:

Over a 12-week period, both groups lost a good amount of weight; but there were no significant differences between them.

Synephrine

Synephrine is an alkaloid, occurring in some plants. It is most commonly extracted from Bitter Orange.

In fat-burners, synephrine is presented as Citrus aurantium (bitter orange) which includes synephrine alkaloids.

When it comes to fat loss, the literature is not that promising.

First off, we’ve got this review looking at 20 studies with 360 total participants. They took either p-synephrine (protoalkaloid) alone or in a combination with other ingredients.

They took the supplements for up to 12 weeks with 44% of participants taking only p-synephrine.

In conclusion, they found that:

In general, bitter orange extract alone (p-synephrine) or in combination with other herbal ingredients did not produce significant adverse events as an increase in heart rate or blood pressure or alter electrocardiographic data, serum chemistry, blood cell counts or urinalysis.

And:

p-Synephrine alone as well as in combination products were shown to increase resting metabolic rate and energy expenditure, and modest increases in weight loss were observed with bitter orange extract/p-synephrine-containing products when given for six to 12 weeks. Longer term studies are needed to further assess the efficacy of these products and affirm their safety under these conditions.

The modest increases don’t sound that promising.

This study had participants take either p-synephrine or in conjunction with other ingredients to determine its effect on RMR.

What they found was rather discouraging:

The group receiving p-synephrine (50 mg) alone exhibited a 65 kcal increase in RMR as compared to the placebo group.

There is an increase in RMR but it’s so insignificant that I doubt it could results in more fat loss over time.

Furthermore, bitter orange can have some bad side effects, especially when taken with caffeine. Here is a direct quote from WebMD:

But bitter orange is POSSIBLY UNSAFE when taken as a supplement for a medical purpose such as weight loss. Bitter orange, particularly when taken with stimulants such as caffeine or caffeine-containing herbs, increases the risk for high blood pressure, fainting, heart attack, stroke, and other severe side effects.

There are reports that bitter orange can trigger headaches, including migraine and cluster headaches, in some people.

Here is the full material.

Forskolin

Forskolin is derived from the herb Coleus forskohlii. In the supplement industry, forskolin is a substance that is often used in fat burners.

The first study worth looking at examined its effect on testosterone levels, fat loss, metabolic rate, and blood pressure in overweight and obese men. The participants took 250 mg of a 10% forskolin-containing coleus twice a day for a total of 50 mg per day.

Here’s what they found:

The increase in serum free testosterone levels could explain the lean body mass gains. Also, testosterone is linked to a decrease in body fat in men(1, 2, 3, 4).

So far so good.

But, there was another study where 23 overweight women received the same dose of coleus forskohlii (500 mg/day) for 12 weeks.

In contrast to the previous study, forskolin had no positive effects on fat loss. But it does seem like forskolin could protect against weight gain.

So, 12 weeks of supplementation with forskolin could improve body composition for men and ward against weight gain in women.

Yohimbine is a substance found in the Pausinystalia yohimbe plant that has been shown to help speed up fat loss.

They assigned the subjects of the study to one of two groups:

One took tablets that contained 20 mg of Yohimbine, twice per day. The other took identical-looking tablets, containing cellulose.

Yohimbine didn’t show benefits for muscle mass and performance. But it did show a reduction in body fat percentage compared to the placebo group.

Yet, despite these findings, you need to take Yohimbine while fasted for it to have an effect. This makes me lose interest in it because it doesn't fit my schedule.

The green tea extract is a substance found in green tea leaves and has been shown to deliver many benefits, one of which is an aid in fat loss.

It can increase fat oxidation rates by as much as 17% in healthy young guys.

It can also induce thermogenesis and increase metabolic rate.

Green tea also contains caffeine which we already covered and found to be a good fat-loss helper.

Green coffee extract comes from unroasted coffee beans. They are naturally green but the roasting makes them change color to brown or black.

The main substance, found in coffee beans that aids in fat loss is chlorogenic acid.

After the coffee bean is roasted, most of the acid is lost so it can only be derived from green coffee beans.

But is the chlorogenic acid the fat-burner it’s claimed to be?

A meta-analysis reviewed 3 randomized clinical trials that met their criteria. There were a total of 142 participants across the 3 studies.

Their conclusion:

The evidence from RCTs seems to indicate that the intake of GCE can promote weight loss. However, several caveats exist. The size of the effect is small, and the clinical relevance of this effect is uncertain. More rigorous trials with longer duration are needed to assess the efficacy and safety of GCE as a weight loss supplement.

So, do fat burners work?

We examined 8 popular ingredients found in most of the popular fat burners out there and we ended up with this:

Five of all 8 substances don’t seem to deliver much if any benefits for fat loss. One can be effective if used in a fasted state (yohimbine). And 2 are actually effective to take on their own or as a part of a fat-burner.

As you can see, most fat burners don’t live up to the hype and are a waste of money.

The shiny label can be alluring but it’s important to understand how each ingredient can help you, and make an informed decision.

To lose fat, you need to be in a caloric deficit. That is a given. But, certain supplements can help enhance the whole process and even make dieting a less tedious process.

Here are the 3 good fat burners, backed by science:

A dose of at least 270 mg a day should be enough to provide the health benefits. But, if you look at the dosages proven to be effective in studies, you’ll notice that 400-600 mg per day is optimal.

Still, if you take green tea extract pills on an empty stomach, do it with caution. They can cause nausea.

Also, keep in mind that certain Green tea extracts contain small amounts of caffeine. Check the label out and if yours has any, take it earlier in the day.

Other than that, you are free to take the pills whenever it’s convenient for you.

Yohimbine only works if you’re training fasted, that much we covered.

As far as dosing goes, research has shown that 0.2 mg per kg of body weight is enough to provide the fat loss benefits. This is especially true if you take it before a workout in a fasted state.

I recommend starting with 0.1 mg per kg to see how your body responds. Some people have reported feeling jittery from yohimbine.

Yohimbine can also raise blood pressure. If you already have high blood pressure, I don’t recommend taking it.

Because of your body’s natural tendency to build up a tolerance towards stimulants, you should cycle caffeine. You can do that in two ways:

1. Cycle caffeine intake on a 4 week on, 1 week off ratio.
2. Have a low-caffeine day and a no-caffeine day each week.

That way, you can ensure that your body doesn’t build too much of a tolerance.

As far as dosing goes, keep your intake to about 5-6 mg per kg of body weight. For reference, a standard 8-ounce cup of brewed coffee contains 95-200 mg of caffeine.

I’d like to end this point with a story from Omar Isuf on his (unfortunate) experiences with fat-burners: