Carnitine is good for weight loss, as it:
- burns belly fat
- is involved in energy production
- improves blood glucose levels
- increases total energy expenditure
However, healthy people don’t need to take carnitine supplements. The body synthesizes high amounts. Also, we get high doses from food.
Does carnitine help you burn more body fat?
Carnitine is a compound found in nearly all cells of the body. The human body can synthesize adequate amounts of carnitine. Moreover, we can get it from animal-derived foods and dietary supplements.
Carnitine plays a key role in fat metabolism and energy production. It transports long-chain fatty acids into the mitochondria to be burned for energy. Hence, carnitine helps burn belly fat for energy.[1]
According to a 2020 study, carnitine supplementation can help overweight people lose weight, decrease Body Mass Index and fat mass.[2]
Another recent study showed that L-carnitine supplementation can significantly decrease body weight, and fat mass. However, only obese and overweight people could benefit from carnitine’s anti-obesity effects! Especially, when combined with moderate exercise and a hypocaloric diet.[3]
Moreover, L-carnitine supplementation may help obese people lose weight because it plays a key role in fat and carbohydrate metabolism, lowers blood glucose levels, improves glucose intolerance in conditions like obesity, decreases insulin resistance, and improves total energy expenditure![4]
But, if you want to lose weight, consuming fewer calories is far more important than getting high amounts of carnitine, either from food, or supplements.[5,6]
Carnitine helps preserve lean body mass while dieting
When we follow a diet low in calories for weight loss, we lose both muscle and fat mass. But, high carnitine intakes from supplements when dieting may prevent muscle mass loss.[7]
Additionally, carnitine is necessary for the synthesis of testosterone! High testosterone levels have been linked to decreased percentage of body fat. Moreover, testosterone is necessary for muscle growth and limiting muscle loss when being in a caloric deficit.
Actually, as carnitine is found mainly in the muscle tissue, it’s beneficial for muscle growth. Carnitine is a popular supplement among athletes and fitness enthusiasts. It acts as a fat burner. In fact, carnitine burns body fat for energy.
Athletes take carnitine to build muscle mass, improve performance, increase energy levels, and even decrease fat percentage. But, there aren’t consistent evidence that carnitine supplements can improve sport performance or body composition in healthy athletes.[8]
First, carnitine supplements may help athletes spare their glycogen storage. Especially, during low-intensity exercise (50% VO2max). It seems that carnitine burns body fat for energy, instead of muscle glycogen. Furthermore, carnitine can reduce muscle lactate accumulation at high intensity exercise.[9]
So, carnitine is beneficial for endurance athletes and athletes who do resistance training for muscle growth and strength. According to a small study, carnitine supplementation increased work output of exercise by 11%.
Moreover, increased carnitine intake can reduce metabolic stress, physical fatigue and promote recovery after exercise. So, it may enhance athletic performance.[10]
Furthermore, L-carnitine supplementation could limit the imbalance between protein synthesis and protein breakdown, supporting muscle growth.[11]
How much carnitine can the human body synthesize a day?
The total carnitine content of the body is about 20 grams for a person weighing 155 pounds (70 kg). Almost all of it is in the muscle tissue.
The human body synthesizes about 0.16 to 0.48 mg/kg of L-carnitine a day. So, a 155 lb person synthesizes between 11 and 34 mg of carnitine a day. Furthermore, kidneys reabsorbs about 95% of carnitine. Therefore, healthy people don’t need to eat foods with carnitine or take carnitine supplements. Even people who follow a plant-based diet and vegans can produce more than enough carnitine.[1,7]
Furthermore, the kidneys efficiently retain carnitine. Thus, even a diet low in carnitine has little impact on the total carnitine content of the body. People may need extra carnitine doses from supplements only under certain conditions.
Foods to boost carnitine synthesis
The human body needs certain compounds for the synthesis of carnitine. We should consume foods with methionine, lysine, vitamin C, and vitamin B6 to help the body produce enough carnitine for increased energy levels and weight loss.[8]
Foods with methionine
Methionine is an essential amino acid for humans. The human body can’t synthesize methionine. We have to get it from diet.
The richest foods in methionine from animal sources are eggs (3.1g per 100g), cod (3g), chicken (2.8g), beef (2.6g), pork (2.6g), and milk (2.5g).[9,10]
But, there are many plant-based foods with high amounts of methionine as well. The richest vegan foods in methionine are rice (2.4g per 100g), corn (2.1g), wheat and oats (1.8g), sesame seeds (1.6g), rye and beans (1.5g), cauliflower (1.4g), Brazil nuts (1.1g). hemp seeds (0.9g), soy protein (0.8g), chia seeds (0.6g), peanuts (0.3g), chickpeas (0.25g), and almonds (0.15g).
Foods with lysine
Lysine is also necessary for the synthesis of carnitine. We must get it from food as well.
Good animal sources of lysine are high-protein foods, such as eggs, meat, and fish. On the other hand, beans and legumes are great plant-based sources of lysine. In fact, beans are among the best foods for weight loss.
Foods with vitamin B6 & C
Last, but not least, we should consume many foods high in vitamin C and vitamin B6 to help the body synthesize carnitine. Moreover, both vitamin B6 and vitamin C are necessary for weight loss and burning belly fat.
Should I eat foods with carnitine to lose weight?
Actually, only foods from animal sources contain high amounts of carnitine. Meet, and dairy are the best sources. Adults who follow mixed diets can get about 60–180 mg of carnitine per day.
On the contrary, vegans get only about 10–12 mg of carnitine from food per day. In fact, vegan foods contain negligible amounts of carnitine. For instance, 2 slices of whole wheat bread contain only 0.2 mg, while half a cup of asparagus contains only 0.1 mg of carnitine.
How much carnitine from supplements to lose weight?
Carnitine is promoted as a dietary supplement for faster weight loss. But, healthy people who follow a well-balanced diet don’t need to take carnitine supplements. The body can synthesize enough carnitine. Furthermore, we can get high doses from food.
In most cases, high doses of carnitine from supplements won’t help you lose significantly more weight. On the contrary, a calorie deficient diet and moderate exercise have a much higher impact on your body composition.
Certainly, you should consult your healthcare provider before taking carnitine supplements. Daily carnitine doses higher than 3 grams may cause side effects, such as nausea, vomiting, abdominal cramps, diarrhea, and bad body odor.
Also, keep in mind that we absorb about 54-86% of L-carnitine from food, as compared to only 5%-25% from oral supplements.[7]