GLP-1 medications, such as semaglutide (Wegovy) and tirzepatide (Mounjaro), have become increasingly popular for weight management and the treatment of type 2 diabetes. These medications work by suppressing appetite, increasing feeling of fullness and slowing gastric emptying.
However, this raises an important nutritional question: if people are eating less, are they still getting enough protein?
What is protein and why is it important?
Protein is one of the three macronutrients, alongside carbohydrates and fats. It plays an important role in building and repairing muscle tissue, supporting the immune system, and producing enzymes and hormones. It also contributes to feelings of fullness after eating.
Maintaining adequate protein intake is particularly important during weight loss. Studies have shown that when taking GLP-1s, of the bodyweight lost approximately 25% was lean body mass, which includes skeletal muscle. (Look et al., 2025) This highlights the importance of maintaining adequate protein intake alongside resistance exercise to help support muscle maintenance during a period of weight loss.
Why is getting enough protein more difficult on GLP-1s?
Although GLP-1 medications can support weight management, their appetite-suppressing effects can make it more challenging to meet nutritional requirements.
Some common reasons include:
· Reduced appetite means people may naturally eat smaller meals
· Feeling fuller for longer can make it difficult to manage larger portions
· Some people may experience side effects including nausea or gastrointestinal symptoms, which further affects food intake
· When eating less overall, people can unintentionally reduce their protein intake
This is where Retain comes in.
Retain is a convenient, ready-to-drink protein shot for anyone looking to increase their protein intake without having to drink a big shake. It has 20g protein and 81kcal in a small 60ml serving. For people struggling with appetite on GLP-1 medication, this smaller-volume protein option can be particularly useful to help meet your protein requirements.
How much protein do you actually need when taking GLP-1s?
Some experts recommend people on GLP-1 medication should consume 1.2-1.6g/kg of ideal body weight per day, which works out as roughly 60-100g per day for most people. Individual requirements will vary depending on factors such as age, body composition, activity levels and individual health needs.
A registered dietitian can help establish suitable requirements for you.
Tips for hitting protein requirements with a low appetite
· Aim for 2-3 retain shots per day alongside smaller meals to help meet your protein target.
· Aim for 25-30g protein every 3-4 hours rather than one huge meal as this can affect absorption
· Have a protein source with every meal e.g. eggs, meat, poltry, fish, dairy, pulses, nuts
Conclusion
GLP-1 medication is a great way to help with weight loss, but it’s important not to overlook nutrition during the process.
When appetite is reduced, meeting your nutritional requirements, particularly protein, can become more challenging. Prioritising protein-rich foods, maintaining physical activity and considering convenient options such as Retain can help support nutritional intake during weight loss.
If you're concerned about your protein intake or meeting your nutritional requirements while taking GLP-1 medication, speak to a registered dietitian for specialist advice.
References:
Look, M., Dunn, J. P., Kushner, R. F., Cao, D., Harris, C., Gibble, T. H., Stefanski, A., & Griffin, R. (2025). Body composition changes during weight reduction with tirzepatide in the SURMOUNT ‐1 study of adults with obesity or overweight. Diabetes, Obesity and Metabolism, 27(5), 2720–2729. https://doi.org/10.1111/dom.16275
