L-Theanine For Weight Loss: How it Works

L-Theanine For Weight Loss: How it Works

L-Theanine, an amino acid primarily found in tea leaves, has garnered attention not only for its stress-reducing and cognitive-enhancing properties but also for its potential role in weight management.

But how exactly does L-Theanine contribute to weight loss?

In this article, we'll explore the science behind L-Theanine's impact on weight loss, its mechanisms of action, and dosage recommendations.

What is L-Theanine?

L-Theanine, a unique amino acid, is primarily found in the leaves of the Camellia sinensis plant, the source of most teas. This compound is the secret behind the calming, relaxing effects of a hot cup of green tea despite its caffeine content. Unlike coffee, which also contains caffeine but lacks L-Theanine, green tea offers a soothing experience.

It's known for its ability to promote relaxation without sedation. It achieves this by increasing levels of neurotransmitters such as GABA, serotonin, and dopamine, which are associated with mood regulation and stress reduction. It also modulates the activity of glutamate, an excitatory neurotransmitter, promoting a state of calm alertness.

Benefits of L-Theanine

  • Promotes relaxation without drowsiness

  • Improves cognitive performance and brain function

  • Reduces acute stress and anxiety

  • Enhances sleep quality

  • Improves mental health

  • Boosts immune system

  • Improves cardiovascular health

  • Synergizes with caffeine

L-Theanine Benefits for Weight Loss

The weight loss benefits of L-Theanine are primarily attributed to its ability to suppress fat accumulation and increase energy expenditure. For example, a study by Zheng et al. (2004) found that caffeine and L-Theanine were responsible for the reduction of body weight increase and fat accumulation in mice.

In a diet-induced obesity study, Peng et al. (2021) discovered that administering 100 mg of L-Theanine to mice improved glucose tolerance and insulin sensitivity, and reduced total cholesterol, and free fatty acids in high-fat diet-fed mice. Improving insulin sensitivity and glucose tolerance is crucial for maintaining a healthy weight.

Although these studies have focused on mice, they still suggest a potential role for L-Theanine in improving metabolic health and supporting weight management efforts in humans. Nonetheless, further research is needed to confirm these findings in human participants.

While no research on humans has identified L-Theanine as a direct fat burner, it's well-known that mood, stress, and depression can lead to overeating and weight gain; thus L-Theanine's ability to promote relaxation and reduce chronic stress levels may indirectly influence weight loss. L-Theanine's ability to increase dopamine levels may contribute to reducing cravings for sugary and fatty foods, thereby supporting adherence to a calorie-controlled diet.

Another significant benefit of L-Theanine is its ability to improve sleep quality. For example, in one study, 30 healthy adults were given either 200 mg of L-Theanine or a placebo every day for four weeks. The researchers found that participants taking L-Theanine took less time to fall asleep, had fewer sleep disturbances, and took fewer sleep medications compared to the placebo group. Chronic sleep disruption is a common issue among individuals struggling with weight management. Thus, by increasing GABA and serotonin levels, L-Theanine promotes relaxation and reduces stress, potentially preventing stress-induced overeating and weight gain.

While the weight loss benefits of L-Theanine are promising, it's important to note that most of the research has been conducted on animals. Therefore, while L-Theanine is not a primary supplement for a weight loss plan, its proven benefits suggest it can complement other weight loss strategies.

Combine L-Theanine with Caffeine to Boost Fat Loss

L-Theanine in combination with caffeine may reduce body weight and fat accumulation. For example, the aforementioned study by Zheng et al. (2004) found that obese mice showed changes associated with abnormal lipid and energy metabolism, which were alleviated by a high-fat diet with green tea containing L-Theanine and caffeine, indicating the mechanism underlying the anti-obesity effects of green tea.

The combination of L-Theanine and caffeine can contribute to reduced fat accumulation primarily by enhancing metabolic rate and promoting fat oxidation. Caffeine increases the body's ability to break down fat cells for energy, a process known as lipolysis, especially when combined with physical activity. Meanwhile, L-Theanine mitigates some of the negative side effects of caffeine, such as jitteriness and increased heart rate, allowing for better focus and potentially more effective workouts. Together, they may create a conducive environment for weight loss by boosting metabolism and improving exercise performance.

L-Theanine, Caffeine, and Catechins: A Powerful Trio

L-Theanine, caffeine, and catechins form a potent trio that can significantly enhance weight loss efforts. Catechins, found in green tea, are known for their antioxidant properties and their ability to boost metabolism, thereby aiding in fat loss. When combined with caffeine, catechins can further enhance thermogenesis, the process by which your body burns calories to produce heat.

Now, add L-Theanine to this mix. As we've discussed, L-Theanine can help mitigate some of the less desirable effects of caffeine, such as jitteriness and increased heart rate. This means you can enjoy the fat-burning benefits of caffeine and catechins without the unwanted side effects.

Moreover, L-Theanine can enhance the cognitive benefits of caffeine, helping you stay focused and alert. This can be particularly beneficial during workouts, allowing you to push harder and burn more calories.

L-Theanine Dosage

The L-Theanine content in green tea varies, but a standard 200 mg cup of green tea typically contains around 8 mg of L-Theanine, and a 200 mg cup of black tea, for instance, contains an estimated 24 mg of L-Theanine. These amounts, while beneficial, are less than the recommended dosage for experiencing the full health benefits of L-Theanine. For these reasons, many people opt for L-Theanine supplementation, which can provide upwards of 100+ mg per serving.

Most fat burners that contain L-Theanine recommend a daily serving range of 100 to 250 mg, like NMN Bio's NAD+ Brain, which packs 100 mg of L-Theanine in each serving. You can take anywhere from one to seven capsules per day, depending on your needs. The dosage largely depends of the amount of caffeine you would like to consume, as each capsule contains 25mg of caffeine too. NAD+ Brain is an excellent addition to your supplement routine when it comes to boosting the natural processes of the body for optimal metabolism. In addition, NAD+ Brain can be taken with NMN Bio's Berberine supplement, that specifically targets weight loss and the activation of the body's innate self-clearing mechanism called autophagy. It also contributes to increased insulin sensitivity. As we now understand how crucial insulin sensitivity is for weight loss, more and more consumers opt in for natural supplements that can support this process, instead of harsher alternatives like Mounjaro or Ozempic.

Conclusion: Does L-Theanine Work for Weight Loss?

The question of whether L-Theanine works for weight loss is a complex one. While animal studies have shown promising results, the lack of human studies makes it difficult to definitively say that L-Theanine is a primary supplement for weight loss. However, its indirect benefits, such as improving sleep quality and mood regulation, suggest that it could play a supportive role in a comprehensive weight loss plan.

The combination of L-Theanine with caffeine and catechins, as found in green tea, appears to be a powerful trio for weight management. The synergistic effects of these compounds may enhance fat loss and boost energy levels, making them a valuable addition to a healthy diet and exercise regimen.

For those seeking the cognitive and potential weight management benefits of L-Theanine in a convenient form, NMN Bio's NAD+ Brain offers a solution. It contains 100 mg of L-Theanine per serving, designed to support mental clarity, focus, and overall brain health, making it a valuable addition to your wellness routine. As always, it's recommended to consult with a healthcare professional before starting any new supplement regimen.

Researched and reviewed by Dr Elena Seranova, Ph.D.

Dr Seranova holds a master's degree in Translational Neuroscience from the University of Sheffield, UK, and a Ph.D in Stem Cell Biology and Autophagy from the University of Birmingham, UK. She is a published author in multiple peer-reviewed journals, including Cell Reports and Developmental Cell.

References

Fry, A., & Rehman, A. Obesity and Sleep. Sleep Foundation. (2023)

Hidese et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. (2019) 

Hursel, R., & Westerterp-Plantenga, M. Catechin- and caffeine-rich teas for control of body weight in humans. The American Journal of Clinical Nutrition. (2013)

Konttinen et al. Depression, emotional eating and long-term weight changes: a population-based prospective study. International Journal of Behavioral Nutrition and Physical Activity. (2019). 

Peng et al. L-Theanine Activates the Browning of White Adipose Tissue Through the AMPK/α-Ketoglutarate/Prdm16 Axis and Ameliorates Diet-Induced Obesity in Mice. Diabetes. (2021) 

Wang et al. How does the tea L-Theanine buffer stress and anxiety. Food Science and Human Wellness. (2022)

Zheng et al. Anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, in mice. In Vivo. (2004)