When it comes to a critical substrate in several metabolic processes, it is very risky to point out that an extra contribution of that same molecule should improve its results.

In relation to the management of body fat, several molecules such as specific fatty acids, ketones, beta-2 / beta-3 agonists, monoacylglycerides and diacylglycerides have been investigated.

But beyond these molecules or in synergy with them, we find the one responsible for the process of transporting free fatty acids, from the interior of the cell to the "oven" where they are burned (mitochondrion) to obtain ATP (cellular energy), the we know as L-carnitine.

Free fatty acids are taken up from the bloodstream or released from fat stores by metabolically active cells (muscle) and transported into the cell (cytosol). If L-carnitine were not available, these free fatty acids would remain in the blood or become part of the stored fat.


As with creatine, it can also be produced in many tissues, so healthy subjects usually have adequate levels of L-carnitine.

Carnitine is an amino acid, or rather a peptide that the body synthesizes from its precursor amino acids (L-lysine and L-Methionine).

But this is so in the best of scenarios, however there are real situations of carnitine deficiency. And this without taking into account the metabolic limit for the endogenous production of each subject, which is also subject to diet, the main source of L-carnitine (meat, fish).

Vegans rely on endogenous production and that typically accounts for more than 85/90 percent of their total L-carnitine. Something very similar to what happens with creatine.

When L-carnitine availability is low our kidneys must work harder to remove it from the urine in order to prevent it from being excreted and lost.

legacies up to here the question is in the air.

Is there a real need to supplement with L-carnitine?

The truth is that yes, numerous L-carnitine deficiencies have been identified in subjects due to problems derived from the transporter, difficulty in carrying L-carnitine into the cell or even its absorption from the diet.

But what about athletes or people with a healthy lifestyle who pursue efficient management of their body fat?

The answer that the research offers us tells us that these studies of L-carnitine
have shown conflicting results, and many even show no additional benefit from L-carnitine supplementation during the diet.

But be careful, because before ruling out L-carnitine, let's analyze whether these studies have considered relevant conditions for athletes, their level of activity and type of diet.

We could find ourselves with a situation similar to creatine, where these supposed strength gains are not as remarkable in sedentary people. So, the question does not arise about L-carnitine and its sufficient concentration to achieve an increase in fatty acid oxidation, if insufficient absorption occurs?

We are not just talking about a weight loss supplement when we refer to carnitine, but it has also been shown to have positive effects on high blood sugar levels and on the cholesterol profile in type 2 diabetics.



L-carnitine studies have focused primarily on calorie-restricted diets, but what about low-carb diets?

A good percentage of those who follow a ketogenic diet become deficient in L-carnitine (absolute or relative), due to a mechanism of excessively high concentration of fatty acids and ketones capable of raising the proportion of "free" L-carnitine.

This is a rough measure of the adequacy of L-carnitine in the mitochondria, and when the ratio becomes too high, it suggests that the body is not capable of handling the demands of all the fat being used to burn calories.

Although in calorie-restricted diets the positive action of L-carnitine is less certain, the most observed consequences of these low-fat diets are fatigue and lack of control over appetite.

Apparently a reduction in the oxidation of fatty acids can lead us to overeat.

So a feasible solution to ensure that fatty acid oxidation is optimized is by supplementing with L-carnitine, as many of the ingredients in that low-fat dietary program may not provide carnitine.

In subjects with metabolic syndrome, the study revealed that compared to a control group those who received L-carnitine supplements (intravenously) had reduced feelings of hunger and fatigue, as well as improvements in weight loss and other positive effects. metabolic changes.

Although a study embarked on the search for genetic abnormalities in healthy adult volunteers may seem exaggerated, it managed to detect a deficiency of L-carnitine that was determined to be a genetic cause.


L-carnitine is likely to help with fat management and weight loss, but not in a miraculously quick way.

Its health benefits are several and not negligible.

It may help in athletic performance, especially when the type of training increases the stimulus for increased or prolonged fatty acid oxidation.

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