GLP-1 Agonists (Ozempic) Management

What are they and how do they work?

Why Might You Be Offered This Treatment? 

GLP-1 receptor agonists are primarily prescribed for:

• Type 2 diabetes management – To help regulate blood sugar levels and reduce the risk of further complications as a result of poorly managed diabetes or insulin resistance. 
• Obesity treatment – For individuals with a BMI of 30+ or a BMI of 27+ with weight-related conditions like high blood pressure, sleep apnea and/or insulin resistance.
• Weight loss assistance – When lifestyle modifications alone have not been effective for weight loss.

Your general practitioner will determine eligibility based on medical history, weight, and metabolic health markers.

But is it the right fit for you? Let’s clarify this. 

What You’ve Heard vs. What You NEED to Know

 What the Media & Celebrities Say:

• "Ozempic makes weight loss effortless!"
• "You’ll never crave junk food again!"
• "Celebrities are losing weight fast on this magic shot!" 

What you need to know: 

While GLP-1 medications can support weight loss, the reality is more complex. Here’s what a practising clinical dietitian wants you to consider:

You Still Need Proper Nutrition & Strength Training:

While these medications can reduce hunger, failing to consume enough nutrients can lead to muscle loss, excessive fatigue, and nutrient deficiencies. A structured diet rich in protein, vitamins, and minerals is essential.

Re-gaining weight is common post-treatment & here’s why: 

Many people regain weight after stopping GLP-1s because they never learn sustainable eating habits. Weight loss isn’t just about the initial drop—it’s about maintaining your results long-term by understanding how to eat for your total daily energy expenditure (TDEE).

You still need a calorie deficit & an active lifestyle to support weight loss: 

GLP-1s mainly suppress appetite and reduce cravings, but you must still be in a calorie deficit to lose weight. The best long-term results come from:

• Daily movement (walking, light activity)
• Strength training (to preserve muscle and metabolism)
• Eating whole, nutrient-dense foods
• Managing stress levels (as chronic stress can increase cravings and impact insulin & metabolism)

GLP-1 medications are a tool, not a cure-all. 

To achieve lasting weight loss and metabolic health, they should be combined with education, structured nutrition, and sustainable lifestyle habits.

How do they work? (The Science) 

Mechanisms of Action: 

Ozempic and Wegovy: 

• Both contain semaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1 RA). Semaglutide mimics the GLP-1 hormone, enhancing insulin secretion, suppressing glucagon release, slowing gastric emptying, and reducing appetite, leading to improved blood sugar control and weight loss. 

Mounjaro: 

• Contains tirzepatide, which acts as a dual agonist for GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptors. This dual action enhances insulin secretion, suppresses glucagon, delays gastric emptying, and reduces appetite, potentially offering greater efficacy in blood sugar control and weight reduction compared to GLP-1 RAs alone.

How do they affect the other systems of your body: 

1. Effects on Nervous System Health

GLP-1 receptor agonists, including semaglutide and tirzepatide, have demonstrated neuroprotective effects and potential benefits in treating neurological conditions. They may influence brain regions involved in appetite regulation and reward, potentially affecting mood and behaviour. However, some users have reported side effects such as mood swings and headaches.

2. Effects on Gastrointestinal Health

Common gastrointestinal side effects include nausea, vomiting, diarrhea, constipation, and delayed gastric emptying. In rare cases, severe gastrointestinal issues like gastroparesis (stomach paralysis) have been reported. 

The impact on gut flora and microbiome balance is not well-documented at this stage, and more research is needed to understand these effects fully. The most significant influence on gut bacteria is the lack of nutrient diversity in most people’s diets, especially with a reduced appetite and a drive for convenience. Many people on GLP-1's are not consuming high quality diets that simultaneously support their gut microbiome, leading to dysbiosis down the track. 

3. Effects on Nutrient Absorption

By slowing gastric emptying, these medications can potentially affect nutrient absorption. While this mechanism contributes to satiety and weight loss, it may also lead to nutritional deficiencies if not paired with a well-rounded diet and caloric targets. For instance, rapid weight loss associated with these drugs has been linked to hair loss, likely exacerbated due to nutrient deficiencies.

4. Long-term Impact on Mental Health and Serotonin Production

The long-term effects on mental health and serotonin production are not fully understood. GLP-1 receptor agonists have shown antidepressant effects in some studies, where others report increased rates of depression, personality changes and mood swings. Suggesting a complex interaction with mental health, and symptom changes will need to continue to be assessed on a case by case basis and self-reporting. 

Weight Management Success Rates

• Semaglutide (Ozempic/Wegovy): Clinical trials have shown significant weight loss in individuals using semaglutide. For example, participants have experienced substantial reductions in body weight over several months of treatment. 
• Tirzepatide (Mounjaro): Studies suggest that tirzepatide may lead to greater weight loss compared to semaglutide. In clinical trials, participants using tirzepatide achieved significant weight reduction, with some studies indicating superior efficacy over semaglutide.

A Dietitian’s checklist to support your health on GLP-1's

1. Aiming to eat 3-4 regular meals throughout the day, consisting of nutrient-dense foods, including lean proteins, healthy fats, fibre-rich vegetables, and complex carbohydrates. 

2. Drinking 2-3L of water per day to support digestion and prevent dehydration. Aim to drink water/fluids away from meal times to prevent yourself from getting too full, too quickly before you finish a meal. 

3.Sufficient daily protein intake – Aim for 1.6-2.2g of protein per kg of body weight daily to maintain lean muscle mass. This may not be possible due to loss of appetite, but aiming to incorporate a source of lean protein at every meal can support your needs. 

4. Avoid Ultra-Processed, Low-Nutrient Foods 

Reduce intake of highly processed foods (including sugary foods) to prioritise quality nutrients and the management of overall caloric intake whilst using a GLP-1. This helps to meet your daily micronutrient needs and to support glucose control, along with gut and nervous system health and mood regulation during your weight loss phase. 

5. Monitor Nutrient Intake 

Ensure adequate levels of iron, B12, folate, and electrolytes, as reduced food intake can lead to deficiencies which cause further metabolic issues and fatigue. Supplement as required and stay on top of routine bloodwork (every 3 months) to help provide a better insight to your specific needs.

6. Include Daily Movement

Aim for 7,000-10,000 steps per day to support metabolism and cardiovascular health. Breaking this up into shorter walk blocks can help with overall energy and fatigue management. 

7. Strength Train at Least 2-3x Per Week 

Prevent muscle loss and support metabolic function (namely, insulin sensitivity) by incorporating regular resistance training

8. Manage Stress 

Monitor overall stress loading from work, relationships, finances and more whilst incorporating daily mindfulness, breathwork, or relaxation techniques to help reduce stress and engage your parasympathetic nervous system (rest and digest side of your nervous system that will support weight loss and metabolic regulation). 

9. Have a Long-Term Plan: 

Work with a dietitian to develop sustainable habits, nutritional literacy and education for weight maintenance post-treatment to maximise your results long term (and the rest of your life)

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