Our body can make the amino acid L-glutamine, often simply called glutamine, and we also get it from several of the protein-dense foods in our diet. Healthy individuals don’t typically need glutamine supplements, but few people take them in the hope of enhancing their weight-loss results.
The proof for this is still preliminary and conflicting, however. These supplements may not be safe for all, so check with your physician before adding them to your daily routine.
How does glutamine work?
Studies indicate that L-glutamine supports weight loss through various mechanisms.
Initially, some studies suggest that L-glutamine supplements alter the gut microbiome’s composition, which is the community of beneficial bacteria in the digestive tract .
Our gut’s microbiomes play a crucial role in several aspects of health, including weight management. What’s more, glutamine can protect against inflammation, which is associated with many chronic conditions, including obesity.
Finally, while research shows that L-glutamine may improve blood sugar control, there’s conflicting proof on whether it affects insulin — the hormone responsible for transporting sugar from the bloodstream into the cells.
However, some animal and human studies indicate that glutamine enhances insulin sensitivity, improving the body’s ability to use insulin efficiently. This can aid weight loss, as impaired insulin sensitivity is likely tied to a higher risk of obesity and weight gain.
Still, more studies are needed to evaluate the relationship between insulin sensitivity and glutamine.
Protein and Weight Loss
If we get our glutamine by consuming more high-protein foods, there may be some weight-loss advantages.
Following a low-calorie diet that is low in fat and high in protein may help us feel fuller and lose more weight than a standard-protein diet that is low in fat with the same number of calories, according to research published in December 2012 edition of the AJCN (“American Journal of Clinical Nutrition”).
This type of diet can also help decrease metabolism during weight loss and minimize muscle loss.
L-Glutamine for Weight Loss
A small preliminary study published in the November 2014 edition of “European Journal of Clinical Nutrition” established that obese women who took glutamine supplements for 4 weeks lost weight even without changing their exercise and diet habits.
When they received a protein supplement for the same amount of time, they didn’t experience any noticeable weight loss. But more extensive studies are needed to verify these advantages and determine what, if any, dose of glutamine is most helpful for weight loss.
Effectiveness for weight loss
Although studies are limited, multiple studies associate glutamine supplements with increased weight loss .
For example, a six-week study in 66 patients with type 2 diabetes noticed that taking 30 grams of glutamine powder daily enhanced multiple risk factors for cardiac disease and reduced both body and belly fat.
Similarly, two-week research using the same amount of glutamine observed decreased waist circumference, a marker for belly fat, in 39 individuals with obesity or overweight .
In another small research, six women who took glutamine supplements for four weeks experienced significant body weight reductions and belly fat without making other lifestyle or dietary changes .
Yet, research in 24 adults showed that taking 6 grams of glutamine led to an increase in meal size, which may hamper weight loss.
Moreover, another investigation that examined the effects of taking a glutamine supplement combined with exercise noted no benefits for muscle performance or body composition.
Remember that all of these studies used tiny sample sizes and only evaluated the short-term effects of glutamine supplements. Therefore, more high-quality research is required.
Effect on Body Composition
Although protein, in general, may help limit the loss of muscle during weight loss, this doesn’t appear to be the case with glutamine. Athletes who took glutamine supplements while on a weight-loss diet didn’t maintain any more muscle than those given a placebo in a study published in the “Journal of Sports Science and Medicine” in 2003.
Glutamine supplements may not be safe if you have liver disease, kidney disease, or Reye syndrome or if you are pregnant or nursing. L-glutamine supplements may also interfere with certain medications, including those used for chemotherapy, HIV, and seizure prevention.
How to use it
Glutamine is found naturally in various foods, including tofu, eggs, milk, and beef. It’s also available in supplement form, including capsules and powders, which are widely considered safe when used as directed.
Most doses range from 500 milligrams (mg) to 3 grams and should be taken every day between meals. In a few studies, doses of up to 30 gm (grams) per day are effective for weight loss.
However, while short-term use is possibly safe, more studies are needed to evaluate the potential side effects of supplementing long term. Start with a smaller dose and increase steadily to assess your tolerance. Moreover, be sure to talk to your medical practitioner before adding any new supplements to your routine.
L-glutamine is an amino acid found in several supplements and foods. Although studies are limited, few studies indicate that it boosts short-term weight loss by altering the gut microbiome’s composition, improving insulin sensitivity, and reducing inflammation.
Nonetheless, its long-term effects aren’t clear. More studies are needed. Moreover, glutamine shouldn’t be considered an instantaneous fix for weight loss. Rather, you should combine it with a balanced diet and healthy lifestyle for better results.