Glutamine and Weight Loss: You Won’t Believe What Science Says

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L-glutamine first came up in the new for its claimed benefit of improving athletic performance. However, the people who actually tried l-glutamine or glutamine were utterly disappointed.

Now, there is also another claim doing rounds of the supplement industry. Many are claiming it can work wonders to facilitate weight loss.

But is there any evidence behind the claim?

Let’s explore!

What is L-Glutamine?

Glutamine is an amino acid just like the BCAAs. It is a non-essential amino acid, and we also find glutamine in several foods.

Additionally, glutamine is present in high levels in our skeletal muscle, liver, and intestines. Generally, most of us will never need glutamine as a supplement.

Now, let’s find out if glutamine can aid in weight loss.

Can L-Glutamine Help You Lose Weight?

Research on glutamine’s effect on weight loss is limited. Therefore, we only have a few studies that all websites use to make claims about the amino acid.

Let’s check out some of the studies and their findings.

Study 1

Our first research is from 2014 and was conducted on 6 overweight and obese females. The scientists gave the women a variety of supplements, including glutamine, over 4 weeks. The women made no other changes to their lifestyle other than taking supplements.

What did the trial find?

At the end of 4 weeks, women taking glutamine noticed a weight loss of around 3 kilos. In addition, they also experienced a reduction in weight circumference.

Study 2

Our next trial is from 2019 and involves 39 overweight adults. The researcher gave the participants 30 grams of alanine or glutamine for 2 weeks. 

By the end of the study, participants taking glutamine reported a reduction in waist circumference. However, the study didn’t measure the weight of the participants and didn’t report any weight loss in the findings.

Study 3

This is by far the largest and longest study conducted on the relationship between l-glutamine and weight loss. In this trial, the scientists recruited 66 volunteers with type 2 diabetes. They received 30 grams of glutamine or a placebo over 6 weeks. 

Like the above studies, the scientists noticed a reduction in waist circumference for those who took glutamine. In addition, they were also able to lose body fat, showing more fat-free mass.

Therefore, the scientists concluded glutamine improves body composition.

Study 4

We are now presenting a study from 2012 that tested glutamine for hormonal response and physical performance. The researchers gave 30 young adults either glutamine or a placebo over 8 weeks.

Among the results, glutamine did not result in any improvement of body composition. It also failed to enhance physical performance.

Therefore, the scientists didn’t find glutamine to aid weight loss.

Study 5

This is an interesting study. It does not involve researching whether glutamine helps us lose weight.

However, the study is important as it found an undesirable effect of the amino acid. Glutamine led the participants to eat more, which can negatively affect weight loss efforts.

What to Conclude

The research on glutamine and weight loss is limited and conflicting. Experts agree there is no evidence to recommend glutamine for losing weight.

Additionally, the studies that reported weight loss are very small, with a few participants. We don’t even have a study that tested glutamine on a hundred or more participants.

Moreover, the studies are of short duration. The maximum length of the studies that reported weight loss was 6 weeks.

Therefore, we need longer trials to find out if glutamine really works.

Another important aspect is the study participants. In most cases, they were overweight or suffering from diseases like diabetes.

As a result, the positive results may not apply to healthy adults. In fact, study number 4 tested glutamine on healthy young adults and found no reduction in weight.

So, we can conclude for now that glutamine doesn’t help us lose weight. In addition, we need more extensive studies to find reliable evidence to prove otherwise.

A Look at Other Evidence

People who claim glutamine helps us lose weight put many reasons forward. Many of us have also read online that glutamine promotes weight loss in several ways like:

  • Improving gut bacteria
  • By boosting blood serum levels of growth hormones

Now, let’s take a closer look at both.

Can L-Glutamine Aid Weight Loss by Improving Gut Bacteria?

Our gut or intestine is home to millions of bacteria. They play a role in vital bodily functions like metabolism and absorption of nutrients from food.

Interestingly, our gut has both bad and good bacteria. We should aim to increase good bacteria to improve our health and immunity system. People also take probiotics to ensure they have enough good bacteria in their intestines.

Now, during obesity, scientists have found people to have more bad bacteria. The theory says you may lose weight by ensuring you have more good bacteria than bad ones.

Generally, people use a single study to show glutamine improves gut bacteria. The scientists of the study also concluded glutamine might help weight loss as it lowered bad bacteria.

However, the study didn’t measure any weight changes. Additionally, the theory is applicable for obese individuals and may not be the same for healthy folks.

Can Glutamine Aid Weight Loss in Any Other Way?

The rest of the cases where glutamine has been found to reduce weight have to do with special conditions. For example, some people say glutamine heals a leaky gut or helps with the non-alcoholic fatty acid disease to aid weight loss.

While these cases may be true, the results don’t apply to healthy individuals. As a result, you have to develop a leaky gut or get fatty liver disease to derive any weight loss benefits.

Trusted sources on the internet also suggest we adopt caution with glutamine. Take the example of for example. It says the evidence on glutamine and weight loss is in its preliminary stages.

Therefore, we need more studies to collect reliable evidence.

Millions of people trust Livestrong in the USA for accurate information. As a result, we decided to stick to reliable sources to provide you with information.

Other sources like Healthline also conclude the same. We need more high-quality research to be able to recommend glutamine for losing weight.

How to Lose Weight the Right Way

We don’t have any shortcuts to losing weight, and glutamine is certainly not one of them. The secret to losing weight is to burn more calories than we eat. The basic step is to reduce our intake of calories and eat a healthy diet.

Additionally, cut out junk food and put a check on carbohydrate intake.

Along with that, put on the running shoes and go jogging. The gym is also a great place to work out and get your heart beating. We should try to burn as many calories as we need to overtake our consumption.

Dieticians can also play a big role in helping us lose weight. We can also try out weight loss supplements that actually work.

However, we still have to remember that supplements are not a shortcut. We have to eat the right food and exercise if we want to shed some kilos. Supplements can only act as a catalyst and give us a push to achieve our weight loss goals.

Final Thoughts

L-glutamine is not the secret to losing weight. Research is still limited, and we don’t have enough scientific evidence. As a result, it is better to exercise and eat a healthy diet to thin down our waist or belly fat. Additionally, we should always take everything with a pinch of salt and research before we believe anything we read online. Like always, we will remain a trusted source and make an effort to provide the right information for better health and wellbeing.


Can glutamine make us lean?

Glutamine has no scientific evidence supporting weight loss in healthy adults. We may be able to lose weight with glutamine and reduce waist circumference if we are overweight. It does not work for healthy adults to lose weight.

Can glutamine curb appetite?

Glutamine may curb appetite by increasing the ratio of good to bad bacteria in our gut. It may provide the body with more energy and enhance glucose metabolism. However, the results may not be very significant.

What happens when we take glutamine?

Glutamine is abundantly available in food. It is very rare to suffer from glutamine deficiency. As a result, taking glutamine may not provide any added benefits for healthy adults. The claims about glutamine and weight loss are not backed by enough scientific evidence.

Does glutamine cause water retention?

Glutamine may increase the water and salt content in our muscles. However, it may not be significant to cause water retention. Consult your trainer or a medical professional for the best advice before starting a supplement.

How long does glutamine take to work?

Glutamine takes a few weeks to work for obese and overweight people. However, it may not lead to significant weight loss or improvement of physical performance. These claims don’t have enough scientific evidence behind them.