By Vanessa Manfredini | Biomedical Scientist and future Nutritionist

In recent years, an acronym has dominated conversations about health, weight loss, and metabolism: GLP-1. Whether it's Ozempic, Wegovy, or any other semaglutide-based medication, the topic is here to stay and has brought a lot of confusion with it.

What is GLP-1? What is it for? Is it only for people with diabetes? And what does diet have to do with all of this?

These are the questions I will answer today based on scientific evidence, without sensationalism and without demonizing any approach. Because my role here is to help you understand your body, not to sell you a magic formula.

"Before wanting to stimulate or block any hormone, it is necessary to understand what it does. Knowledge is the basis of any intelligent health decision."

What is GLP-1?

GLP-1 stands for Glucagon-Like Peptide-1. It is a hormone naturally produced by our own body, in the L cells of the small intestine, especially in the ileum and colon.

It is released in response to food intake and plays a central role in regulating glucose metabolism and satiety. In other words: it is one of the main responsible for signaling to your brain that you have eaten enough.

GLP-1 is an incretin hormone, meaning it is released by the intestine after a meal and stimulates insulin secretion in a glucose-dependent manner. This means that it only stimulates insulin when glucose is elevated, which makes it much safer than many other approaches for glycemic control.

What does GLP-1 do in the body?

The effects of GLP-1 are broad and affect several body systems:

In the pancreas

• Stimulates insulin production when glucose is elevated
• Inhibits glucagon release – a hormone that increases blood glucose
• Protects pancreatic beta cells, responsible for insulin production

In the stomach and intestine

• Slows gastric emptying – food stays longer in the stomach, prolonging satiety
• Reduces appetite and the urge to overeat
• Decreases intestinal motility after meals

In the brain

• Acts on the hypothalamus promoting satiety
• Reduces the reward response to highly palatable foods – decreases excessive pleasure in eating ultra-processed foods
• May have neuroprotective effects, still under study

In the heart and vessels

• Studies show cardioprotective effects – reduction of cardiovascular risk
• Improves inflammatory markers associated with cardiovascular disease

Why has GLP-1 become a topic of discussion?

The story begins with type 2 diabetes. Researchers noticed that people with this condition had a reduced response to GLP-1 after meals – the incretin effect was compromised. From there, they began to develop medications that mimic or potentiate the action of this hormone.

The first were the so-called incretinomimetics – medications that mimic GLP-1. Over time, semaglutide emerged, a long-acting GLP-1 analog that can be administered once a week.

Ozempic was initially approved for type 2 diabetes. But studies showed something unexpected: in addition to controlling glucose, people lost significant weight. That's when the medication left endocrinology offices and hit headlines and social media.

GLP-1 and gut microbiota: the connection few talk about

Here comes my perspective as a Biomedical Scientist passionate about the gut: there is a fascinating connection between the gut microbiota and GLP-1 production.

The L cells that produce GLP-1 are located in the intestine, and the microbiota directly influences the functioning of these cells. Studies show that:

• Butyrate-producing bacteria such as Akkermansia muciniphila and Faecalibacterium prausnitzii stimulate GLP-1 production
• Intestinal dysbiosis is associated with a reduced GLP-1 response after meals
• Diets rich in fiber and fermented foods increase natural GLP-1 production
• Butyrate produced by the fermentation of fibers by good bacteria is one of the main stimulators of L cells

In other words: taking care of the microbiota is not just a strategy for the gut. It is also a way to optimize the natural production of hormones that regulate your metabolism, including GLP-1.

"Your gut produces GLP-1. The quality of what you eat determines how much it will produce."

How to naturally stimulate GLP-1 through diet?

This is the practical and most important part for those who do not use medication or want to enhance the effects for those who do. Diet has a real and documented impact on GLP-1 production:

Fermentable and prebiotic fibers

They are the fuel for bacteria that stimulate L cells. Rich and accessible sources in Brazil:

• Beans, lentils, and chickpeas – consume regularly, it's the basis of Brazilian diet for a good reason
• Rolled oats – oat beta-glucan has a proven effect on GLP-1 stimulation
• Green banana and cooked and cooled cassava – rich in resistant starch
• Garlic, onion, and leek – sources of inulin and fructooligosaccharides
• Dark leafy greens – spinach, kale, arugula

Quality proteins

Protein is one of the macronutrients with the greatest ability to stimulate GLP-1. Include it in all meals:

• Eggs – complete source of amino acids and easily accessible
• Chicken, fish, and lean meats
• Natural yogurt and kefir – have the bonus of also being probiotics
• Legumes – beans and lentils combine plant protein with prebiotic fiber
• Nuts and seeds – walnuts, Brazil nuts, chia, flaxseed

Healthy fats

Good quality fats slow gastric emptying and enhance satiety along with GLP-1:

• Extra virgin olive oil
• Avocado – rich in monounsaturated fat and fiber
• Nuts and seeds
• Fatty fish such as sardines, salmon, and tuna

Fermented foods

By taking care of the microbiota that stimulates L cells, fermented foods play an indirect but important role:

• Milk or water Kefir
• Unsweetened natural whole yogurt
• Curd
• Homemade sauerkraut
• Kombucha 
• *If you want the recipe, leave it in the comments of this post and I will make it available in the Free Resources!

What reduces GLP-1 production

• Diets rich in saturated fat and refined sugar – reduce GLP-1 sensitivity
• Ultra-processed foods – harm the microbiota that stimulates L cells
• Meals without fiber and protein – stimulate less hormone production
• Sedentary lifestyle – physical activity increases GLP-1 sensitivity

And for those who use Ozempic or semaglutide, what changes?

For those who use these medications with medical indication, diet remains fundamental and perhaps even more important than without the medication. This is because:

• The medication reduces appetite, but it doesn't choose what you eat – nutritional quality remains your responsibility
• Accelerated weight loss without adequate protein can lead to muscle mass loss – a real risk that needs to be monitored
• Gastrointestinal side effects – nausea, reflux, constipation – are much more manageable with a well-planned diet
• In the long term, eating habits will determine weight maintenance after medication use

That's why nutritional support during the use of GLP-1 analogs is not optional – it is essential.

Conclusion

GLP-1 is not a fad – it is a fascinating hormone that your body naturally produces and plays a central role in metabolism, satiety, and cardiovascular health.

Medications that mimic this hormone are here to stay and have a legitimate role in the treatment of diabetes and obesity. But diet remains the most accessible, sustainable, and safe way to optimize natural GLP-1 production, and taking care of the gut microbiota is a fundamental part of this equation.

As always, there is no silver bullet. There is science, consistency, and an individualized approach to your body.

"Ozempic can mimic GLP-1. But the right diet can make your body produce it better. And the two are not enemies."

Did you like this content?

Leave your comment below – have you heard about GLP-1 before? Do you have any questions about the medications or how to stimulate this hormone naturally? Tell me! And follow me on Instagram @vanessamanfredini.nutri for more scientific content in your daily life! 🌿

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With care and science, Vanessa 🌹

This content is based on scientific studies about GLP-1 analogs. Main references:

1. 1. Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine, 2021.
2. 2. Drucker DJ. Mechanisms of action and therapeutic application of GLP-1. Cell Metabolism, 2018.
3. 3. Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine, 2022.