L-Carnitine For Fat Loss

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Whether you’re an athlete looking to improve your endurance or simply looking for a natural way to support your overall health, L-carnitine may be just what you need.

In this blog post, we’ll take a closer look at L-carnitine and explore its potential uses and benefits for enhancing your health and well-being.

What is L-Carnitine?

L-carnitine is a naturally occurring amino acid that is produced in the liver and kidneys from the essential amino acids lysine and methionine.

It plays an important role in the body’s energy metabolism by transporting long-chain fatty acids into the mitochondria of cells, where they can be oxidized and used as a source of energy.

Specifically, L-carnitine functions as a carrier molecule that shuttles fatty acids from the cytosol of cells (where they are stored) into the mitochondria (where they are burned for energy) by binding to them and transporting them across the inner mitochondrial membrane.

This allows fatty acids to be used as an energy source, which is especially important during periods of prolonged physical activity or during periods of low carbohydrate intake, when glucose is less available.

L-carnitine in animal foods

We naturally produce small amounts of L-carnitine in our body, however on occasion, we will need to get it from our diets. It is found in a variety of foods, particularly animal-based foods. Here are some of the best food sources of L-carnitine:

• Beef: Beef is one of the richest sources of L-carnitine, with about 81 mg per 3-ounce serving.
• Pork: Pork is another good source of L-carnitine, with about 24-27 mg per 3-ounce serving.
• Chicken: Chicken is a good source of L-carnitine, with about 3-5 mg per 3-ounce serving.
• Fish: Fish like cod, haddock, and salmon are good sources of L-carnitine, with about 5-10 mg per 3-ounce serving.
• Milk: Milk is a good source of L-carnitine, with about 8 mg per 8-ounce serving.
• Cheese: Cheese is another good source of L-carnitine, with about 3-7 mg per ounce.
• Lamb: Lamb is a good source of L-carnitine, with about 24 mg per 3-ounce serving.
• Venison: Venison is a good source of L-carnitine, with about 19 mg per 3-ounce serving.
• Bison: Bison is a good source of L-carnitine, with about 9 mg per 3-ounce serving.
• Turkey: Turkey is a good source of L-carnitine, with about 4-5 mg per 3-ounce serving.
• Duck: Duck is a good source of L-carnitine, with about 4 mg per 3-ounce serving.
• Cod liver oil: Cod liver oil is a good source of L-carnitine, with about 2-3 mg per teaspoon.
• Shrimp: Shrimp is a good source of L-carnitine, with about 1-2 mg per 3-ounce serving.
• Crab: Crab is a good source of L-carnitine, with about 1-2 mg per 3-ounce serving.
• Scallops: Scallops are a good source of L-carnitine, with about 1-2 mg per 3-ounce serving.

It’s important to note that food processing can affect the L-carnitine content of foods. For example, some processed meats like hot dogs and deli meats may have lower L-carnitine content than fresh meats.

L-carnitine in vegetarian foods

Vegetarian and vegan sources of L-carnitine are generally lower, but some plant-based foods do contain small amounts of L-carnitine. These include:

• Avocado: Avocado is a good source of L-carnitine, with about 2 mg per avocado.
• Asparagus: Asparagus is a good source of L-carnitine, with about 0.1-0.2 mg per 1/2 cup serving.
• Tempeh: Tempeh is a good source of L-carnitine, with about 3-4 mg per 3-ounce serving.
• Whole wheat bread: Whole wheat bread is a moderate source of L-carnitine, with about 0.2 mg per slice.
• Corn: Corn is a moderate source of L-carnitine, with about 0.1-0.2 mg per 1/2 cup serving.
• Sesame seeds: Sesame seeds are a moderate source of L-carnitine, with about 0.1-0.2 mg per tablespoon.
• Pumpkin seeds: Pumpkin seeds are a moderate source of L-carnitine, with about 0.1-0.2 mg per tablespoon.
• Peanut butter: Peanut butter is a moderate source of L-carnitine, with about 0.1-0.2 mg per tablespoon.

Although vegan diets typically have low amounts of carnitine in them due to the lack of animal products, vegans usually don’t need to supplement it since their body is able to produce enough.

Types of L-carnitine

Acetyl-L-Carnitine vs L-Carnitine

L-carnitine and acetyl-L-carnitine are two closely related compounds that share a similar chemical structure, but differ in terms of their specific biochemical functions and potential health benefits.

Acetyl-L-carnitine (ALCAR), is a modified form of L-carnitine that has an additional acetyl group attached to it. This modification enhances its ability to cross the blood-brain barrier and enter the brain, where it can support cognitive function and protect against age-related cognitive decline.

While both L-carnitine and acetyl-L-carnitine have been studied for a variety of health conditions, the research suggests that they may be more effective for different purposes.

L-carnitine has been more extensively researched for cardiovascular health, including reducing the risk of heart disease and improving exercise tolerance in people with heart failure.

On the other hand, acetyl-L-carnitine has been more widely studied for neurological conditions, including Alzheimer’s disease, Parkinson’s disease, and peripheral neuropathy.

Other forms of L-carnitine

Propionyl-L-carnitine (PLCAR) and Glycine Propionyl-L-carnitine (GPLC) are two other forms of L-carnitine that have different chemical structures and properties. Here is a rundown of how they compare to L-carnitine:

• Chemical structure: PLCAR has a propionyl group attached to it, while GPLC is a combination of glycine and propionyl-L-carnitine.
• Properties: PLCAR is thought to have a more significant impact on cardiovascular health, while GPLC may be more effective at increasing blood flow and reducing muscle damage during exercise.
• Common uses: Both PLCAR and GPLC are often used as dietary supplements to support athletic performance, exercise recovery, and cardiovascular health. GPLC is also sometimes used as a treatment for erectile dysfunction.
• Cost and availability: Both PLCAR and GPLC are available as dietary supplements in various forms, such as capsules or powders. They are typically much more expensive and harder to find than regular L-carnitine.

Overall, while PLCAR and GPLC may have some theoretically unique benefits compared to regular L-carnitine, they are all ultimately broken down into L-carnitine in the body and provide similar benefits.

Diet vs supplements

The type of L-carnitine found in foods and supplements is the same molecule. Carnitine is found in the highest quantities in red meat like steak or beef. On average, 4 ounces of steak provides about 100 mg of L-carnitine.

Most studies use a dose of around 2-3 grams of L-carnitine per day. So to obtain a useful 2 g dose of L-carnitine, you’d need to eat 80 ounces of steak. That’s 5 pounds of steak, with a whopping 5500 kcal.

So if you wanted to take L-carnitine like in the research studies, getting it from supplements is probably the easiest way to go. Supplements are designed to deliver higher amounts of the molecule in a more bioavailable form.

That being said, foods that contain L-carnitine like red meats, chicken, and fish are good sources of protein for a weight loss diet, and help to increase fullness during meals.

Benefits for weight loss

L-carnitine is often marketed as a weight loss or fat loss supplement, and while more research is needed to fully understand its effects, some studies suggest that it may have the following potential benefits:

• Increased fat burning: L-carnitine may help increase the use of fat for energy during exercise, which can contribute to greater fat burning and weight loss.
• Improved exercise performance: L-carnitine may enhance athletic performance and reduce muscle damage and soreness, which could help support regular exercise and weight loss efforts.
• Reduced fatigue: L-carnitine may help reduce fatigue and improve energy levels, which can help support weight loss by promoting more physical activity.

The most convincing uses for L-carnitine in weight loss involve improving the efficiency of exercise to burn fat, by helping to convert fat into energy.

The idea is that by supplementing the body with large amounts of carnitine, the body is more easily able to pull energy from fat cells, leading to increased fat burning and usage during exercise.

Some athletes take L-carnitine to improve the intensity and recovery times of their workouts.

Other health benefits

L-carnitine has been researched for its potential benefits in a variety of medical conditions, including:

• Heart disease: L-carnitine may help improve heart function and reduce symptoms in people with heart disease, including angina and heart failure, and help these people to exercise more without tiring out as quickly.
• Diabetes: L-carnitine may help improve insulin sensitivity and blood sugar control in people with type 2 diabetes.
• Male infertility: L-carnitine may help improve sperm quality and motility in men with infertility.
• Muscle disorders: L-carnitine may help improve muscle function and reduce symptoms in people with certain muscle disorders, such as myopathy and muscular dystrophy.
• PCOS: L-carnitine may help improve the chances of ovulation and pregnancy in women with PCOS who do not respond well to medications like clomiphene or human chorionic gonadotropin (HCG).

Side effects

L-carnitine supplementation is generally considered safe for most people when used in appropriate doses. The most common side effects include:

• Digestive upset: Some people may experience nausea, vomiting, diarrhea, or stomach pain when taking L-carnitine supplements.
• Fishy odor: L-carnitine supplements can produce a fishy odor in urine, sweat, and breath. This is a harmless side effect and can be minimized by taking lower doses or using different forms of L-carnitine.

Also, L-carnitine may interfere with the absorption of thyroid hormone replacement medications, such as levothyroxine.

L-carnitine and heart disease

There is some research that suggests that people with higher levels of L-carnitine in the blood may be associated with a higher risk of cardiovascular disease.

However, this is likely just an association, rather than being caused by the high levels of L-carnitine. Allow me to explain.

You see, we already know that people who eat a lot of red meat like beef and pork, might already have a higher risk of cardiovascular disease.

Red meat is high in L-carnitine, so naturally, people who eat lots of red meat will have higher levels of L-carnitine in their blood.

It’s more likely that the high levels of red meat are causing increased cardiovascular risks, rather than the high levels of L-carnitine, which is just a byproduct of eating a lot of red meat.

In fact, L-carnitine supplements at regular doses may help reduce the risk of heart problems, such as abnormal heartbeats and angina.

Research shows that taking L-carnitine does not increase the risk of heart failure or heart attack happening again.

Other studies suggest that L-carnitine supplements likely do not have an effect on reducing the risk of death or heart problems in people who have had a previous heart attack.

L-carnitine and TMAO

However, when taken in excessively high doses, L-carnitine can be metabolized into a compound called trimethylamine-N-oxide (TMAO), which has been linked to an increased risk of heart disease.

TMAO is a byproduct of the gut microbiome, and it is produced when certain bacteria in the gut break down L-carnitine.

High levels of TMAO in the blood have been associated with an increased risk of heart attacks, strokes, and death from heart disease.

The exact mechanism by which TMAO increases the risk of heart disease is not fully understood, but it is thought to be related to its effects on the walls of the arteries.

TMAO may promote the formation of plaque in the arteries, which can lead to narrowing of the arteries and an increased risk of heart disease.

Therefore, taking excessively high doses of L-carnitine and its subsequent metabolism into TMAO may be harmful to health, especially for people who are at an increased risk of heart disease.

How effective is it for weight loss?

For weight loss, the results of these studies have been mixed, but it seems that taking doses of 2 grams daily for up to 6 months can help overweight or obese individuals lose a small amount of weight and reduce their body mass index (BMI).

However, taking L-carnitine did not affect weight or BMI in patients with a BMI under 25 kg/m2 or in patients undergoing hemodialysis.

Also, one study found that taking L-carnitine 2 grams twice daily for 8 weeks along with exercise did not reduce body weight in obese females.

For improving exercise, studies on the use of L-carnitine for athletic performance have had mixed results.

Some studies have shown that taking 2 grams of L-carnitine before exercise or daily for up to 6 weeks can improve athletic performance, increase endurance, and reduce muscle pain after exercise in male athletes and healthy untrained males. But other studies have not supported these findings.

Some studies have shown that taking 1-2 grams of L-carnitine before exercise or 4 grams daily for 2 weeks can decrease lactate accumulation and increase oxygen uptake, power output, and time to anabolic threshold during exercise. However, other studies have shown no improvement in these outcomes.

Overall, L-carnitine appears to be more helpful as an exercise aid in men, helping to slightly improve the intensity and duration of exercise.

Whether this translates to weight loss probably depends highly on the exercises that are done.

Unfortunately, when taken outside of an exercise setting, L-carnitine doesn’t appear to have much effects on weight loss by itself.

Also, labeling L-carnitine as a “fat burner” is somewhat misleading since although it is involved with the fat burning process, research has shown that supplementing additional L-carnitine doesn’t seem to increase this metabolic process any more, at least not enough to help with additional fat burning.

How to use it for weight loss

If you’ve already included exercise into your weight loss protocol, and are looking for ways to improve your exercise intensity and duration to help burn more fat, supplementing L-carnitine may help, particularly if you have some cardiovascular issues that make it more difficult for you to exercise.

The research would suggest that this effect is more pronounced in men than it is for women, at least for weight or fat loss.

Or, if you’d like to be more physically active and are on a diet that restricts animal products like a vegan diet, but your low energy and sore muscles prevent you from being as physically active as you’d like, L-carnitine might improve you energy and help you to keep your level of physical activity high.

In both cases, L-carnitine would be helpful for weight loss mostly if you’re already exercising regularly, or plan to significantly increase your level of physical activity.

If you’re not physically active, or just focusing on your diet for weight loss, L-carnitine might not do anything for you.

Top supplement choices

• L-Carnitine (caps) – 2 to 4 caps / day
• L-Carnitine (powder) – 2 to 4 scoops / day

Learn more about

• Best exercises to lose belly fat
• Exercising for Weight Loss
• Other weight loss supplements

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