When you consider the process of burning fat, and fat burners in specific, you will more than likely start looking into the process of thermogenesis. Thermogenesis describes the generation of body heat and is also linked to the dynamic and thermic effect of food. Our metabolism in general works by taking consumed food and absorbing it, utilizing it, and triggering loads of accompanying cellular processes. Whenever we consume food, by default we trigger some kind of caloric need, which is our metabolism working hard to processes this food. This will allow us to generate a little bit of body heat. Therefore, the notion that you should eat frequently to boost your metabolism due to this small increase in body heat is incorrect. As the health industry has revolutionized more popular trends such as fasting. The point is that body temperature does elevate slightly after consuming food simply because the body is burning those calories.

There are the three pinnacles that should require all our focus when it comes to fat loss and in choosing a fat burner:

  • Firstly, will be the thermogenesis and the use of calories that generates heat.
  • Secondly will be your basal metabolic rate or the resting metabolic rate, which is the calories that we naturally burn at rest.
  • Lastly, we have to look at the level of physical activity, which in itself is a method of generating heat. The metabolism in general is greatly dictated by the amount of lean body mass that it must work with. The lean body mass is everything in your body that is tissue such as our muscles and organs, not anything compromised of fat. Taking into account the amount of lean body mass on a person determines what their metabolism is like.

Studies have shown when you look at this on a per pound basis if people have the same amount of lean body mass their metabolism is usually the same. This implies that if we all had the same amount of body fat it would be a lot easier for us to determine what our overall caloric needs and metabolism would be. For example, if you were to have two 200-pound people, one of these having 30% body fat, and the other 5% body fat, the person with the 5% body fat will have the higher resting metabolic rate. Simply put, muscle tissue is more metabolically active which means it demands more calories and when you demand those calories you generate heat. Thus, it is not just about this calorie in and calories out equation but it’s more about the heat that is generated. If you need more calories, you create more heat and as a result, you need to work out harder so you can burn more fat.

So, when we start to look at fat burners, we need to consider how this works. Most fat burners that are available are marketed as thermogenic. The interesting thing is that thermogenics can’t actually increase your core body temperature like a lot of fat burners claim, as it all comes down to the beta-adrenergic receptors and our overall catecholamine response. This is basically our adrenaline and norepinephrine. When we have this beta-adrenergic activity, the need for these catecholamines, adrenalin, and norepinephrine increases. Now, this response is similar to what happens in our bodies when we have a fright, get nervous, or even excited. Your heart rate starts to increase and so does your caloric need. This happens simply because you have more movement and you have more metabolic demands. Whether you need more glucose, more fat, or even more protein, your body is consuming everything at that specific point in time, causing a thermic effect. Looking at popular fat burners, most share the same main general ingredients – Caffeine. This is the biggest ingredient due to its ability to stimulate beta 2 and beta 3 adrenergic receptors, therefore drawing out more adrenaline and epinephrine. This is exactly again why your body temperature goes up and why your heart rate increases. The next big ingredient is EGCG which is common in most fat burners. This is very effective as it spares the existing catecholamines preventing them from getting reabsorbed and thus they get utilized more efficiently. Then we start to consider selective ingredients such as carnitine, which is very interesting as carnitine allows more fat to get into the cell. Basically, when you have stored fat, you have triglycerides which are free fatty acids bound to a glycerol molecule. Carnitine is required for that free fatty acid that has been released to get into the mitochondria. If you have an increase in fat that is being mobilized, because you are working out or something similar causing thermogenesis to be elevated above normal, you will have more fats being broken down and going into the bloodstream. This will increase the body’s demand for carnitine, therefore at some point, you will become deficient in carnitine and as such will not burn fat optimally. Supplementing with carnitine can adequately promote fat mobilization and as such place you in a position to burn fat optimally while you workout. 

We need to also consider capsaicin as this is an ingredient very prevalent in most fat burners. Most studies show that capsaicin can increase your core body temperature, however, more recent studies have shown that it increases your body temperature by stimulating beta-adrenergic receptors such as the aforementioned catecholamines, adrenaline, and norepinephrine. This all comes back to the simple method of quickly increasing energy so that the demand for glucose, fat, and protein going through gluconeogenesis is increased.

Lastly, probably most of your popular fat burners on the market contain the ingredient Yohimbine. Yohimbine is similar to capsaicin in that it affects the body by stimulating the sympathetic nervous system which is responsible for activating the release of catecholamines. Many people assume that yohimbine works by speeding up your basal metabolic rate and suppresses your appetite much like caffeine and while yohimbine is a mild stimulant and there is some evidence that it can help suppress your appetite there is a bit more to its fat burning mechanisms. Yohimbine works on the alpha receptors that are responsible for hindering fat breakdown meaning wherever these receptors are in abundance, you will have a hard time losing fat in those areas. What alpha receptors do is inhibit the way your body burns the fat by inhibiting or constricting blood flow. Yohimbine can then effectively block these alpha receptors and since alpha receptors block fat breakdown and yohimbine blocks alpha receptors the net result will be an increase in the fat breakdown in that area.

A recent study on fat burners done by the Journal of the International Society of Sports Nutrition examined 10 resistance-trained males with similar lean body mass and had them perform 2 separate workouts. In one session they did their workout as usual, and in the next session, they were instructed to wait 24 hours. This followed with half the group taking a placebo and the other half taking a general fat loss supplement. They then measured the resting metabolic rate, heart rate, and blood pressure at different time intervals following the consumption of the fat burner and placebo. The results came back very enlightening as they found that in the group that consumed the fat burner, after 60 minutes they had a resting metabolic rate which had increased 7.8 percent versus 3.3 percent in the placebo group. After a 120 min period, the resting metabolic rate in the fat burner group increases 6.9 percent versus 3.1 percent in the placebo group. Then after a 180 min period, they found that it increased 9.1 percent versus 2.1 percent in the placebo group.


The conclusion we make from this is that when a fat burner is taken pre-workout, there is a more efficient fat burn that ultimately occurred because of the increase in resting metabolic rate. Thus, it is determined that by increasing your catecholamines through stimulation of your beta-adrenergic receptors, you do burn more fat as a result of thermogenesis. They indirectly help you burn more fat; however, you have to be working out! This process requires stimulus inactivity, meaning you can’t just drink fat burners and expect to burn fat as the fat needs to be mobilized.  Fat burners can be a very effective tool to aid you in losing those stubborn few pounds, however, always remember that supplements cannot do all the work and as such exercise and proper nutrition should always accompany all your weight loss supplements to ensure you get optimal results.

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